The eastern town of Slovyansk has been the scene of some particularly heavy fighting. (Source: CNN)
The tensions between Ukraine, Russia and the U.S. have increased after a passenger airliner crashed in an region controlled of pro-Russian rebels.
The U.S. will sanction Russia after weeks of tension between Ukraine and Russia. Crimea voted to become a Russian region, while pro-Russian protestors continue to seize buildings in the eastern part of Ukraine.