Anti-government protesters help a wounded protester during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. Thousands of angry anti-government protesters clashed with police in a new eruption of violence following new maneuvering by Russia and the European Union to gain influence over this former Soviet republic. (AP Photo/Efrem Lukatsky)

Anti-government protesters clash with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. Thousands of angry anti-government protesters clashed with police in a new eruption of violence following new maneuvering by Russia and the European Union to gain influence over this former Soviet republic. (AP Photo/Efrem Lukatsky)

Anti-government protesters clash with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, in Ukraine, Wednesday, Feb. 19, 2014. Thousands of angry anti-government protesters clashed with police in a new eruption of violence following new maneuvering by Russia and the European Union to gain influence over this former Soviet republic. (AP Photo/Efrem Lukatsky)

An anti-government protester, center, throw a Molotov cocktail during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Efrem Lukatsky)

Anti-government protesters protected themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. . (AP Photo/Efrem Lukatsky)

Anti-government protesters protected themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Efrem Lukatsky)

An anti-government protester throws a stone during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Efrem Lukatsky)

Anti-government protesters protected themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Efrem Lukatsky)

Anti-government protesters use a catapult during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Efrem Lukatsky)

Anti-government protesters, left, stand behind a barricade during clashes with riot police in front of monuments to city founders in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. The burnt building at left are the offices of a trade union. (AP Photo/Efrem Lukatsky)

Anti-government protesters protected themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Anti-government protesters protected themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Anti-government protesters relax at the barricades during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. A roundup of some of the international reactions. (AP Photo/Efrem Lukatsky)

Anti-government protesters protected themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Anti-government protesters protected themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Anti-government protesters protect themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Anti-government protesters clash with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Anti-government protesters protect themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

An anti-government protester relaxes during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Anti-government protesters gather stones during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Protesters dig for stones during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. A roundup of some of the international reactions. (AP Photo/Efrem Lukatsky)

An Orthodox priest stands at the barricades during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

Anti-government protesters protect themselves with shields during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Efrem Lukatsky)

An anti-government protester walks away during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Sergei Chuzavkov)

An anti-government protester stands behind a barricade during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. The burnt building at left are the offices of a trade union. (AP Photo/Efrem Lukatsky)

Anti-government protesters throw stones during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. A roundup of some of the international reactions. (AP Photo/Efrem Lukatsky)

An anti-government protester stands behind a barricade during clashes with riot police in Kiev's Independence Square, the epicenter of the country's current unrest, Kiev, Ukraine, Wednesday, Feb. 19, 2014. The deadly clashes in Ukraine's capital have drawn sharp reactions from Washington, generated talk of possible European Union sanctions and led to a Kremlin statement blaming Europe and the West. (AP Photo/Efrem Lukatsky)

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19, 2014 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19, 2014 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19, 2014 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters protect themselves behind shields as they clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

An anti-government protesters uses a slingshot during clashes with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters protect themselves behind shields as they clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters throw cobblestones as they clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

An anti-government protester throws a cobblestone during clashes with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters throw cobblestones as they clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters protect themselves behind shields during clashes with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters hold Ukrainian flags as they clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

An anti-government protester takes part in clashes with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesteras take part in clashes with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protester clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protester clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

An anti-government protester wearing a helmet stands on Independence Square in Kiev during clashes with the police early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

TOPSHOTS An anti-government protesters uses a slingshot during clashes with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

TOPSHOTS Anti-government protesters throw cobblestones as they clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

TOPSHOTS Anti-government protester clash with the police on Independence Square in Kiev early on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/SERGEI SUPINSKY

Anti-government protesters stand on their barricades during clashes with police on Independence Square in Kiev on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/GENYA SAVILOV

Anti-government protesters wearing hoods and helmets stand behind a barricade during clashes with police on Independence Square in Kiev on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/GENYA SAVILOV

Some anti-government protesters rest while others (unseen) clash with police on Independence Square in Kiev on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/GENYA SAVILOV

Residents hand out food to anti-government protesters on Independence square in Kiev on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO/GENYA SAVILOV

Anti-government protesters partially block a road with tyres and mobile artillery taken from government troops in the western Ukrainian city of Lviv, on February 19, 2014. Anti-government protesters in Kiev braced on February 19 for a fresh assault by riot police after a day of fierce clashes left at least 25 people dead in Ukraine's worst crisis since the collapse of the Soviet Union. AFP PHOTO/ YURIY DYACHYSHYN

An anti-government protesters stands by a road that was partially blocked by tyres and mobile artillery taken from government troops in the western Ukrainian city of Lviv, on February 19, 2014. Anti-government protesters in Kiev braced on February 19 for a fresh assault by riot police after a day of fierce clashes left at least 25 people dead in Ukraine's worst crisis since the collapse of the Soviet Union. AFP PHOTO/ YURIY DYACHYSHYN

People look on February 19, 2014 at burnt cars that were set on fire outside the regional police headquarters by the anti-government protesters during the night in Lviv, western Ukraine. Anti-government protesters in Kiev braced on February 19 for a fresh assault by riot police after a day of fierce clashes left at least 25 people dead in Ukraine's worst crisis since the collapse of the Soviet Union. AFP PHOTO/ YURIY DYACHYSHYN

This image taken on February 18, 2014 and released on February 19, 2014 by Skybox Imaging shows an aerial view of central Kiev, with "Maidan" dubbed Independence square (C) and smoke billowing from clashes between anti-government protestors and police (C, R near the stadium). Ukraine's security service on February 19, 2014 announced a nationwide "anti-terrorist" operation in response to deadly anti-government protests. "The National Security Service and Ukrainian Anti-Terrorist Centre have taken the decision to conduct an anti-terrorist operation across the territory of Ukraine," security agency head Oleksandr Yakimenko said in a statement. RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / SKYBOX IMAGING" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This image taken on February 18, 2014 and released on February 19, 2014 by Skybox Imaging shows an aerial view of central Kiev, with "Maidan" dubbed Independence square (on the L) and smoke billowing from clashes between anti-government protestors and police (C, near the stadium). Ukraine's security service on February 19, 2014 announced a nationwide "anti-terrorist" operation in response to deadly anti-government protests. "The National Security Service and Ukrainian Anti-Terrorist Centre have taken the decision to conduct an anti-terrorist operation across the territory of Ukraine," security agency head Oleksandr Yakimenko said in a statement. RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / SKYBOX IMAGING" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

This image taken on February 18, 2014 and released on February 19, 2014 by Skybox Imaging shows an aerial view of central Kiev, with "Maidan" dubbed Independence square (on the L) and smoke billowing from clashes between anti-government protestors and police (C, near the stadium). Ukraine's security service on February 19, 2014 announced a nationwide "anti-terrorist" operation in response to deadly anti-government protests. "The National Security Service and Ukrainian Anti-Terrorist Centre have taken the decision to conduct an anti-terrorist operation across the territory of Ukraine," security agency head Oleksandr Yakimenko said in a statement. RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / SKYBOX IMAGING" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS

Anti-government protesters dig up cobblestones to use them as rocks against riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO / PIERO QUARANTA

A wounded anti-government protester is evacuated during clashes with riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO / PIERO QUARANTA

Anti-government protesters dig up cobblestones to use them as rocks against riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO / PIERO QUARANTA

A photo taken on February 19, 2014 shows the remains of the Trade Union building on Kiev's Independence Square. The building was set on fire late February 18 during clashes between anti-government protesters and riot police and burned all night. UN human rights chief Navi Pillay called on February 19 for calm in Ukraine and demanded an independent investigation into deadly clashes between police and protesters. AFP PHOTO / PIERO QUARANTA

A anti-government protester climbs on a barricade during clashes with riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. Ukraine's security service on February 19 announced a nationwide "anti-terrorist" operation in response to deadly anti-government protests. "The National Security Service and Ukrainian Anti-Terrorist Centre have taken the decision to conduct an anti-terrorist operation across the territory of Ukraine," security agency head Oleksandr Yakimenko said in a statement. AFP PHOTO / PIERO QUARANTA

Anti-government protesters clash with riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO / SANDRO MADDALENA

Anti-government protesters prepapre Molotov cocktails during clashes with riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO / SANDRO MADDALENA

An anti-government protester wears a gas mask during clashes with riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. Ukraine's security service on February 19 announced a nationwide "anti-terrorist" operation in response to deadly anti-government protests. "The National Security Service and Ukrainian Anti-Terrorist Centre have taken the decision to conduct an anti-terrorist operation across the territory of Ukraine," security agency head Oleksandr Yakimenko said in a statement. AFP PHOTO / SANDRO MADDALENA

An anti-government protester prepares to throw a cobblestone towards riot police during clashes on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. Ukraine's security service on February 19 announced a nationwide "anti-terrorist" operation in response to deadly anti-government protests. "The National Security Service and Ukrainian Anti-Terrorist Centre have taken the decision to conduct an anti-terrorist operation across the territory of Ukraine," security agency head Oleksandr Yakimenko said in a statement. AFP PHOTO / SANDRO MADDALENA

An anti-government protester wrapped in the Ukrainian national flag stands by a barricade during clashes with riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. Ukraine's security service on February 19 announced a nationwide "anti-terrorist" operation in response to deadly anti-government protests. "The National Security Service and Ukrainian Anti-Terrorist Centre have taken the decision to conduct an anti-terrorist operation across the territory of Ukraine," security agency head Oleksandr Yakimenko said in a statement. AFP PHOTO / SANDRO MADDALENA

Anti-government protesters stand on Kiev's Independence square during clashes with riot police on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO / PIERO QUARANTA

TOPSHOTS An anti-government protester uses a slingshot to throw stones towards riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. As dawn rose over Kiev's battered city centre, protesters hurled paving stones and Molotov cocktails at lines of riot police that had pushed into the heart of the devastated protest camp on Independence Square. AFP PHOTO / PIERO QUARANTA

TOPSHOTS A anti-government protester climbs on a barricade during clashes with riot police on Kiev's Independence square on February 19, 2014. Protesters braced on February 19 for a fresh assault by riot police in central Kiev after a day of clashes left at least 25 people dead in the worst violence since the start of Ukraine's three-month political crisis. Ukraine's security service on February 19 announced a nationwide "anti-terrorist" operation in response to deadly anti-government protests. "The National Security Service and Ukrainian Anti-Terrorist Centre have taken the decision to conduct an anti-terrorist operation across the territory of Ukraine," security agency head Oleksandr Yakimenko said in a statement. AFP PHOTO / PIERO QUARANTA

TOPSHOTS Policemen run amid flames during clashes with anti-government protesters in front of the Ukrainian Parliament in Kiev on February 18, 2014. Police on Tuesday fired rubber bullets at stone-throwing protesters as they demonstrated close to Ukraine's parliament in Kiev, an AFP reporter at the scene said. Police also responded with smoke bombs after protesters hurled paving stones at them as they sought to get closer to the heavily-fortified parliament building. AFP PHOTO/ ANATOLII STEPANOV

TOPSHOTS Police clash with anti-government protesters in Kiev on February 18, 2014. Police on Tuesday fired rubber bullets at stone-throwing protesters as they demonstrated close to Ukraine's parliament in Kiev, an AFP reporter at the scene said. Police also responded with smoke bombs after protesters hurled paving stones at them as they sought to get closer to the heavily-fortified parliament building. AFP PHOTO/ ANATOLII BOIKO

TOPSHOTS Anti-government protesters clash with police in Kiev on February 18, 2014. Police on Tuesday fired rubber bullets at stone-throwing protesters as they demonstrated close to Ukraine's parliament in Kiev, an AFP reporter at the scene said. Police also responded with smoke bombs after protesters hurled paving stones at them as they sought to get closer to the heavily-fortified parliament building. AFP PHOTO/ ANATOLII STEPANOV