BEIJING (AP) _ Authorities set the final death toll from a November coal mine explosion in northern China at 51 after rescuers dug out the body of the last missing miner, the government's China Daily said Wednesday.

Authorities have concluded that the Nov. 26 blast at the Hulun Bei'er No. 2 coal mine, near China's border with Mongolia, came after miners struck a pocket of explosive gas trapped deep beneath the earth, the newspaper said.

More than 300 workers were in the mine when the gas exploded. Eleven were killed and another 40 were initially reported missing. None of those miners survived, with rescuers finding the last body Monday, the report said.

Chinese mines often lack appropriate ventilation that would allow deadly gases to escape during mining. Frequent explosions have helped make China's mines the world's deadliest, with 4,883 people killed in the first 10 months of this year.

China released a set of new regulations last month requiring routine safety inspections and proper training for miners, but previous rules already in place have been only spottily enforced.