Seven people were killed in a coal and gas outburst at a mine shaft Tuesday night in the county of Weixin, southwest China's Yunnan Province, authorities said Wednesday. The accident occurred at 8:30 p.m. Tuesday when 20 miners were working at a shaft of Nanfeng Coal Mine in Luobu Township. Thirteen of them managed to escape, Xinhua quoted a spokesman with the county government as saying. By 7 a.m. Wednesday, all bodies had been identified, and relevant managers of the mine has been in police custody, according to the spokesman. The cause of the accident is under further investigation.