(Reuters) – Ukraine’s president on Monday threatened military action after pro-Russian separatists occupying government buildings in the east ignored an ultimatum to leave and another group of rebels attacked a police headquarters in the troubled region. Acting president Oleksander Turchinov also held out the possibility of a referendum on the future shape of the Ukrainian state, partly addressing demands made in the largely Russian-speaking east for more control over their local affairs. As the 9 […]