A gas blast tore through a Chinese coal mine, killing at least 60 people in the country's deadliest mine accident this year, the government said Thursday. Officials reported that another 88 were missing and chances of finding them alive were slim.

Some 446 people were at work in the Daping Mine (search) southwest of Beijing at the time of the explosion and 298 escaped alive, said Sun Huashan, deputy administrator of the State Administration of Work Safety.

The official Xinhua News Agency (search) said the explosion occurred Wednesday night in Henan province. The agency cited local officials saying 60 miners were confirmed dead and more than 1,000 rescuers was searching for 88 others. Xinhua said most of the miners whose bodies had been found so far died of suffocation in the toxic fumes.

"The chances of the workers surviving are rather slim," Sun said at a news conference in Beijing.

State television said the gas density in the mine shot up from 2 percent to 40 percent in less than three minutes. Poor ventilation is a common problem in China's accident-plagued mines.

The cause of the accident was under investigation, said an official reached by telephone at the Henan Province Coal Mine Safety Inspection Bureau (search). He refused to give his name.

The state-owned Daping Mine employs 4,100 people and is located in the Songshan Mountains, about 25 miles southwest of the major industrial city of Zhengzhou.

Bodies of the dead were laid out at the mine offices under green canvas tarps for identification, Xinhua said. It said 20 injured miners were hospitalized, four of them in serious condition.

State television showed rescue workers in orange jumpsuits and hardhats rushing to the scene holding what appeared to be oxygen canisters and first aid kits.

"This accident exposed many problems in our works, such as that the fundamental facilities of coal mine work are still very weak and many loopholes still exist in our management on work safety," said Sun, the safety official.

He also suggested that pressure to raise coal production amid Chinese energy shortages might be partly to blame: "Overproduction in coal mines is a common thing due to the energy shortage in our country."

China's coal mines are the world's deadliest, with thousands of deaths reported every year in explosions, underground floods and other accidents often blamed on negligence or lack of safety equipment.

Fires, floods and other accidents in coal mines killed 4,153 people in the first nine months of this year, the government said Thursday in a regular report on industrial safety.

It said that figure was down 13 percent from the same period last year, due largely to a nationwide safety crackdown.