A police officer directs a Syrian visitor waiting to take pictures with an Olympic torch at the Athletes' Village at the Olympic Park, two days before the opening ceremony of the Olympic Games. AP PHOTO / JAE C. HONG

Visitors and police walk past the Olympic Stadium in the Olympic Park before the last rehearsal of the Opening Ceremony in east London on July 25, 2012, two days before the start of the London 2012 Olympic Games. AFP PHOTO / JOHANNES EISELE

The ArcelorMittal steel sculpture by artist Anish Kapoor outside the Olympic Stadium in the Olympic Park in London on Wednesday, 25th July, 2012. LEHTIKUVA / Timo Jaakonaho *** FINLAND OUT. NO THIRD PARTY SALES. ***

The horse Oregon De La Vigine of France rider Denis Mesples have a cover with a skull on the head during a training session at Greenwich Park, the site for the equestrian and modern pentathlon events at the 2012 Summer Olympics, Wednesday, July 25, 2012, in London. (AP Photo/Markus Schreiber)

Veins are seen on the horse Clifton Promise while mounted by New Zealand rider Jonathan Paget during training for the equestrian eventing competition in Greenwich Park at the 2012 Summer Olympics, Wednesday, July 25, 2012, in London. (AP Photo/David Goldman)

A woman walks past a wall decorated with Great Britain's flag at the Olympic Park in London on July 24, 2012 just days ahead of the London 2012 Olympic Games. AFP PHOTO / ADEK BERRY

The ArcelorMittal Orbit steel sculpture by Anish Kapoor and the Olympic Stadium in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

Tourists in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

Tourists in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

Volunteers perform in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

Final preparations under way in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

The Olympic Stadium in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

British Army soldiers and the Olympic Stadium in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

British Army soldiers and the Olympic Stadium in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

People in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

The ArcelorMittal Orbit steel sculpture by Anish Kapoor in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

The Aquatics Center in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

British Army soldiers in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

The ArcelorMittal Orbit steel sculpture by Anish Kapoor and the Olympic Stadium in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***

British Army soldiers in the Olympic Park in London on Tuesday, 24th July, 2012. LEHTIKUVA / Heikki Saukkomaa *** FINLAND OUT. NO THIRD PARTY SALES. ***