People look at unidentified men in military fatigues blocking a base of the Ukrainian frontier guard unit in Balaklava on March 1, 2014. Ukraine's border guard service said that about 300 armed men were attempting to seize its main headquarters in the Crimean port city of Sevastopol under orders from Russian Defence Minister Sergei Shoigu. AFP PHOTO/ VIKTOR DRACHEV

People look at unidentified men in military fatigues blocking a base of the Ukrainian frontier guard unit in Balaklava on March 1, 2014. Ukraine's border guard service said that about 300 armed men were attempting to seize its main headquarters in the Crimean port city of Sevastopol under orders from Russian Defence Minister Sergei Shoigu. AFP PHOTO/ VIKTOR DRACHEV

Unidentified soldiers block a road to Ukrainian military airport Belbek not far from Sevastopol on February 28, 2014. Ukraine accused Russia of staging an "armed invasion" of Crimea on Friday and appealed to the West to guarantee its territorial integrity after pro-Moscow gunmen took control of the peninsula's main airport. Unidentified armed men were patrolling outside of Crimea's main airport early Friday while gunmen were also reported to have seized another airfield on the southwest of the peninsula where ethnic Russians are a majority and where pro-Moscow sentiment runs high. AFP PHOTO/ VASILIY BATANOV

Unidentified soldiers block a road to Ukrainian military airport Belbek not far from Sevastopol on February 28, 2014. Ukraine accused Russia of staging an "armed invasion" of Crimea on Friday and appealed to the West to guarantee its territorial integrity after pro-Moscow gunmen took control of the peninsula's main airport. Unidentified armed men were patrolling outside of Crimea's main airport early Friday while gunmen were also reported to have seized another airfield on the southwest of the peninsula where ethnic Russians are a majority and where pro-Moscow sentiment runs high. AFP PHOTO/ VASILIY BATANOV

Unidentified armed men patrol outside of Simferopol airport, on February 28, 2014. Ukraine accused today Russia of staging an "armed invasion" of Crimea and appealed to the West to guarantee its territorial integrity after pro-Moscow gunmen took control of the peninsula's main airport.AFP PHOTO / VIKTOR DRACHEV

Unidentified armed men patrol outside of Simferopol airport, on February 28, 2014. Ukraine accused today Russia of staging an "armed invasion" of Crimea and appealed to the West to guarantee its territorial integrity after pro-Moscow gunmen took control of the peninsula's main airport.AFP PHOTO / VIKTOR DRACHEV

One of the unidentified armed men patrols outside of Simferopol airport, on February 28, 2014. Ukraine accused today Russia of staging an "armed invasion" of Crimea and appealed to the West to guarantee its territorial integrity after pro-Moscow gunmen took control of the peninsula's main airport.AFP PHOTO / VIKTOR DRACHEV

Unidentified armed men patrol outside of the Simferopol airport on February 28, 2014. Ukraine accused today Russia of staging an "armed invasion" of Crimea and appealed to the West to guarantee its territorial integrity after pro-Moscow gunmen took control of the peninsula's main airport. AFP PHOTO/ GENYA SAVILOV