Battle in Kiev (photo)

Riot police attack anti-government protesters during clashes in Kiev, February 18, 2014. Ukrainian riot police advanced on the heart of 12-week-old protests against President Viktor Yanukovich on Tuesday and security forces set a deadline to end disturbances after at least five protesters were reported killed in a day of clashes. REUTERS/Maks Levin

An anti-government protester throws bottles during clashes with riot police at the Independence Square in Kiev February 18, 2014. REUTERS/Vasily Fedosenko

Wounded people are seen after clashes with riot police in central Kiev February 18, 2014. REUTERS//Vlad Sodel

An anti-government protester throws a Molotov cocktail while attacking an office of the pro-presidential Party of the Regions in Kiev February 18, 2014. REUTERS/Gleb Garanich

Interior Ministry members clash with anti-government protesters during a rally in Kiev February 18, 2014. REUTERS/Vlad Sodel

Interior Ministry members injured during clashes with anti-government protesters are escorted by colleagues in Kiev, February 18, 2014. REUTERS/Stringer

Anti-government protesters hold a photo of Ukraine's President Viktor Yanukovich as they attack an office of the pro-presidential Party of the Regions in Kiev, February 18, 2014. REUTERS/Maksym Kudymets

Wounded people are seen after clashes with riot police in central Kiev February 18, 2014. REUTERS//Vlad Sodel

Anti-government protesters attack an office of the pro-presidential Party of the Regions in Kiev, February 18, 2014. REUTERS/Maksym Kudymets

Riot police officers and a woman take cover behind shields during clashes between anti-government protesters with police in Kiev, February 18, 2014. REUTERS/Maks Levin

 Interior ministry members take cover behind shields during clashes with anti-government protesters in Kiev February 18, 2014. REUTERS/Konstantin Chernichkin

Ukranian riot police take cover behind their shields during clashes with anti-government protesters near Independence Square in Kiev February 18, 2014. REUTERS/Konstantin Chernichkin

Anti-government protesters aim their weapons during clashes with riot police at Independence Square in Kiev February 18, 2014. REUTERS/Vasily Fedosenko