DHAKA: Russian President Vladimir Putin has warned that Ukraine is "on the verge of civil war" after Kiev sent in troops against pro-Russia separatists.

Putin, in a phone call to German Chancellor Angela Merkel, described the move as a "sharp escalation".     

Ukraine announced the start of an "anti-terrorist operation" in the east of the country on Tuesday, says BBC.                 

Moscow annexed Crimea last month and is believed to have thousands of troops massed along its border with Ukraine.

"The Russian president remarked that the sharp escalation of the conflict has placed the country, in effect, on the verge of civil war," the Kremlin said of Putin`s conversation with Merkel.   

But it said that both leaders "emphasised the importance" of planned four-way talks on Thursday between senior diplomats from Russia, the EU, the US and Ukraine.

BDST: 1220 HRS, APR 16, 2014