TOPSHOTS Pro-Russia protester wearing gas masks storm a regional police building as one prepares a petrol bomb in the eastern Ukrainian city of Horlivka (Gorlovka), near Donetsk, on April 14, 2014.About 100 pro-Russia protesters armed with bats and rocks stormed a police station in the east Ukrainian town of Horlivka on April 14, smashing its windows and grabbing metal shields from police. Ukraine's interim president on April 14 made a dramatic about-face aimed at defusing tensions in the separatist east by backing a national referendum on turning the ex-Soviet republic into a federation with broader regional rights. AFP PHOTO/ ALEXEY KRAVTSOV