Thirty-three miners have been confirmed dead after a coal mine blast in the rebel-held city of Donetsk near the battle front in eastern Ukraine.

None of those trapped in the rubble survived.

Mine officials said the explosion was most likely caused by gas and not linked to fighting at the nearby frontline in the war between Moscow-backed rebels and Ukraine government forces.

Nevertheless, Kiev suggested the war had made the disaster worse, accusing the separatists of holding up a rescue effort by restricting access.

Outside the gates of the Zasyadko mine, about 30 relatives clamoured for information about any survivors.

The sister of one miner who was in the pit at the time of the explosion, Alexei Novoselsky, stood in tears.

"Tell me, are there survivors? Why are you concealing the truth," she said as a local rescue services employee tried to calm her.

Eduard Dmitrenko, a miner who went down the affected shaft after the blast, said it was unlikely anyone would have been found alive.

Donetsk has been the scene of heavy fighting between Moscow-backed separatist rebels, who control the area, and forces loyal to the government in Kiev.

A ceasefire has sharply reduced the violence in the past week.

The neighbourhood around the mine had come under artillery fire, with fragments from Grad rockets visible on surrounding roads.