A voter casts a ballot during a referendum in the eastern Ukrainian city of Slaviansk
A voter casts a ballot during a referendum in the eastern Ukrainian city of Slaviansk May 11, 2014. Ukrainian leader Oleksander Turchinov warned pro-Russian eastern regions they would be stepping into the abyss if they voted for self-rule on Sunday in a referendum that has raised Western fears of a slide to full civil war. REUTERS/Baz Ratner (UKRAINE - Tags: POLITICS CIVIL UNREST ELECTIONS)