A gas blast at the Zasyadko mine in Ukraine has killed 33 workers, and a further 16 have been hospitalised.
Local officials confirmed 70 people had been working in the mine at the time of the blast on Wednesday, which trapped 33 workers in the rubble.
The Zasyadko mine, located near the Ukranian Rebel held city of Donetsk, had an explosion in 2007 which killed 106 people.
Reuters reported a worker said there had been four explosions at the mine in the last 23 years.
Mine officials said the explosion was not related to fighting in the area, and was most probably caused by gas.
The neighbourhood around the mine has previously come under artillery fire.
Ukrainian prime minister Arseny Yatseniuk said rescue workers were dispatched to the mine by central authorities in Kiev, however “the Russian terrorists did not let them reach the scene of the accident,” he said.
“That is why I publically address the president of the Russian Federation to give instructions to these bastards to allow our mine rescue brigades to save the lives of these miners,” the president told a conference on Wednesday.
Miners who escaped said it was unlikely any survivors would be found.
Since conflict began in Ukraine, coal mining output has fallen 22 per cent to 65 million tonnes, which has caused shortages at power plants.