Ukraine tightens grip on Kramatorsk ahead of four-power talks on crisis
Russia's President Putin Putin tells German Chancellor in a telephone call late on Tuesday that Kiev has “embarked on an anti-constitutional course” by using the army against rebels

Ukrainian forces tightened their grip on the eastern town of Kramatorsk on Wednesday after securing control over an airfield from pro-Russian separatist militiamen, prompting Russian President Vladimir Putin to warn of the risk of civil war.
Seven armoured personnel carriers bearing the Ukrainian flag rumbled into the mainly Russian-speaking town in a show of force against Moscow-backed gunmen who have occupied public buildings in 10 eastern towns and cities in the last week.
The attempt by the Kiev government to reassert control slowly without bloodshed came on the eve of four-power talks in Geneva on Thursday at which the Russian and Ukrainian foreign ministers will meet for the first time in the presence of the United States and the European Union.
Russia, which has refused to recognise Ukraine’s pro-Western government since Moscow-backed President Viktor Yanukovich was ousted by mass protests in February, sought to dramatise the instability in its neighbour ahead of the crucial meeting.
Putin told German Chancellor Angela Merkel in a telephone call late on Tuesday that Kiev had “embarked on an anti-constitutional course” by using the army against the rebels.