The bodies of at least 13 Ukrainian soldiers were delivered to a morgue close to the battleground town of Debaltseve on Wednesday as government forces retreated from the key transport hub, a morgue official said.

"The corpses of 13 Ukrainian servicemen were brought in today," Ruslan Fedonyuk, director of the morgue in the government-held town of Artemivsk, told AFP.

"They delivered them this morning and we have now organised a vehicle that will collect them and transport that for further autopsies and registration," he said.

An AFP journalist at the scene saw body bags containing five corpses lying next to a refrigerated van parked outside the morgue and another five bodies wearing camouflage covered by sheets inside. 

A row of makeshift coffins was lined up in the snow apparently waiting to transport the bodies. 

Government forces on Wednesday retreated from the flashpoint town of Debaltseve, in a bitter defeat for Kiev following weeks of fierce battles with pro-Russian rebels.

Ukraine and the US has accused Russia of piling in troops and weapons to spearhead the assault, which continued despite the start of a nominal ceasefire on Sunday.(+++++)