GUIYANG - All the 13 miners trapped by a coal mine blast in Southwest China's Guizhou province were confirmed dead, rescuers said Thursday, seven days after the accident.

The last body was retrieved at 7:30 am Thursday after rescuers cleaned 381,000 cubic meters of gas and 1,400 cubic meters of coal out of the shaft at Jinjia Coal Mine, said a spokesman with the accident rescue and relief headquarters.

The accident happened around 5:30 pm on January 18, trapping 13 at a shaft of the coal mine in Panxian County, Liupanshui City. High density of gas in the shaft had hampered rescue before the bodies were recovered.

With annual production capacity of 1.8 million tons, Jinjia is a state-owned coal mine operated by the Guizhou Panjiang Clean Coal Co Ltd.

An investigation into the cause of the accident is underway.