BEIJING - A gas explosion at a coal mine killed 13 people on Friday, Xinhua news agency said, adding to a grim set of statistics from the world's deadliest mining industry.

Thirteen people had been confirmed dead and seven were injured at the mine in the southwestern province of Sichuan, the agency said.

The injured were all out of danger, Lin Shucheng, head of the provincial work safety supervision administration, told Xinhua.

The accident happened at 3:11 a.m. at the Furong Coal Mine in the city of Yibin when 20 miners were working underground, Xinhua said.

Rescuers had recovered the bodies of the dead as of 2:00 p.m. on Friday,  Lin who was supervising the rescue operation was quoted as saying by Xinhua, adding the cause of the accident is under investigation.

As a major coal producer of the province, the state-owned mine in Gongxian County has an annual production capacity of 1.2 million tons.

The mine reported a gas explosion in December 2001, which left nine dead and four injured, Xinhua said.

China is struggling to meet booming demand for coal which fuels about 70 percent of its energy consumption.