"As of 1200 today, 110 [Ukrainian soldiers] have been reported taken captive and 31 are still missing. But the search for the soldiers and establishing their whereabouts continues," Seleznev said.

The Ukrainian authorities say they ordered a withdrawal of Ukrainian troops from the besieged town of Debatltseve on Wednesday, but soldiers returning from the battlefield said that the decision to pull out was taken by commanders on the ground.

Ukrainian soldiers also gave far higher numbers of dead and wounded in Debaltseve than the official figures, with some saying hundreds had been killed.

They also complained of not being given adequate support from the Ukrainian General Staff, saying they lacked food, ammunition, and supporting fire from artillery.