Fourteen workers were killed in a gas explosion at a coal mine in north China's Shanxi province, state media and officials reported Tuesday.

A 32-hour rescue operation was called off after three bodies were recovered at a colliery in Jinzhong city, state news agency Xinhua reported.

Li Yuanzhen, the spokeswoman for the Heshun county government, earlier told AFP that eleven bodies had been found following Monday's blast and that three remained in the mine.

Two workers who were working near the entrance to the mine shaft escaped unharmed.

Rescuers worked through the night to clear debris from the shaft entrance and inserted a pipe to improve ventilation.

A Heshun county official in charge of the local coal sector was sacked late Monday after the blast, Xinhua said, citing a government spokesman.

Officials launched an investigation into the cause of the blast.

China's coal mines are notoriously dangerous.

Official figures show that more than 3,200 workers died in collieries last year, but independent labour groups say the actual figure could be much higher, as many accidents are covered up in order to avoid costly mine shutdowns.