A Pro-Russian force guards a barricade outside a regional police building seized by armed men in Slovyansk Sunday. Ukraine, which launched an "anti-terrorist operation" in the eastern town, says one of its officers has been killed in a clash near the town. Genya Savilov/AFP/Getty Images hide caption

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Members of Ukraine's Svoboda party fight with members of the Communist Party in Ukraine's Parliament Tuesday, during a debate over a law toughening responsibility for separatism. AFP/AFP/Getty Images hide caption

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A man holds a Soviet Union flag during a pro-Russia rally in Simferopol, Crimea's Lenin Square Sunday. In Kiev, Ukrainian Prime Minister Arseniy Yatsenyuk vows not to give "an inch" of territory to Russia. Filippo Monteforte/AFP/Getty Images hide caption

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Ukrainian President Viktor Yanukovych (right) and opposition leader Vitali Klitschko shake hands Friday after signing an agreement that diplomats hope will end the bloodshed in Kiev. Tim Brakemeier/EPA/Landov hide caption

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An injured man is carried away Thursday after more clashes between anti-government protesters and police in Kiev. Yannis Behrakis /Reuters/Landov hide caption

itoggle caption Yannis Behrakis /Reuters/Landov