Twelve miners are dead and five are trapped after a gas outburst at a coal mine in southwest China's Guizhou Province Tuesday morning.

Sixty miners were working underground when the accident happened at the Mingyang Coal Mine in Changgang Township, Renhuai City, at around 9:30 a.m., the provincial work safety bureau said.

Some 29 workers managed to escape the gassy shaft themselves while rescuers saved 14 others.

The rescued miners were taken to hospital as they had inhaled toxic gas.

Rescuers have retrieved the bodies of 10 miners and located the bodies of two others.

The provincial work safety watchdog is investigating the cause of the accident.

Mingyang Coal Mine is a licensed private coal mine with a production capacity of 90,000 tonnes per year.