An explosion tore through a coal mine in northern China on Wednesday, leaving at least 54 workers dead and another 22 missing, the government said, the third disaster in recent weeks involving scores of miners.

The latest incident highlights the Chinese government's continuing battle with mine safety despite repeated crackdowns and pledges by the leadership to improve conditions.

Last year, more than 6,000 miners were killed in fires, floods, cave-ins and explosions, making China's shafts the world's deadliest. Corruption, lax safety rules and poor equipment are among factors often blamed for the accidents.

Wednesday's explosion occurred at the privately run Liuguantun Colliery in Tangshan, a city in Hebei province, when 186 miners were underground, the official Xinhua News Agency said, increasing the number of workers underground from a previously reported 123.

Thirty-one miners were immediately rescued but three later died. The bodies of 51 miners had been recovered from the mine by early Thursday, bringing the death toll to 54, it said.

Rescuers were searching for 22 still trapped in the mine, Xinhua said.