An accident at a coal mine in China trapped more than 40 people underground on Thursday, state media and officials said, the latest in a string of incidents to hit the country's vast mining industry.
Rescuers were at the scene of the accident, which occurred early Thursday morning in the southwestern province of Yunnan, the official Xinhua news agency said.
A local government statement said the miners were trapped by a "gas explosion," but this could not be confirmed, and Xinhua said emergency workers referred only to a "gas leak".
The accident comes days after a blast in a coal mine in the central province of Henan trapped dozens of workers underground, most of whom were eventually pulled out after a 40-hour rescue operation, but 10 were killed.
Coal mine accidents are common in China, where work safety is often neglected by bosses seeking a quick profit.
Last year, 2,433 people died in coal mining accidents in the country, according to official statistics -- a rate of more than six workers per day. Campaigners suggest the true figure is likely to be far higher.
Last month, a gas explosion at a state-owned coal mine in the central province of Hunan left 29 miners dead.
Earlier in October, blasts at mines in the southwestern city of Chongqing and the northern province of Shaanxi killed 13 and 11 miners respectively.
China's rapid economic growth has caused demand for energy, including coal, to surge.
The Asian nation is the world's leading consumer of coal, relying on it for 70 percent of its growing energy needs.
Over the past eight years it has on average built one coal-fired power station a week. And with the arrival of winter, mines are operating at full capacity.