Chinese mines have a terrible safety record

Thirty-seven men were working underground at the Zuoquan county mine when the blast occurred.

Ten men were rescued soon after the explosion, but two people still remain unaccounted for, said an official with the Shanxi Coal Mine Supervision Bureau.

"Rescue workers are still trying to locate them, but the chance of finding them alive is slim," the official told the French news agency AFP.

At least 65 miners have been killed in two other mine explosions in the last two weeks, and five remain missing.

A preliminary investigation into Monday's accident showed that the blast was caused by the ignition of gas which had built up in the mine's ventilator during a half-hour power cut, according to China's official news agency Xinhua.

Safety rules dictate that the miners should have been evacuated from the pit during the power switch-off, and not allowed back into the mine until the gas had dispersed, Xinhua said.

In the wake of the latest disaster, provincial officials in Shanxi have ordered that all local mines - except five large state-owned ones - be shut down for a week for safety checks.

"All these accidents have been caused by negligence and loose management. We should learn from these lessons," Governor Liu Zhenhua was quoted as telling state media.

Chinese coal mines have the worst safety record in the world.

Official figures indicate that more than 5,000 people were killed last year alone, while other estimates suggest the figure could be much higher.

Many such incidents occur in privately owned mines, which lack operating licences and adequate safety equipment.

China relies heavily on the coal industry for its energy needs.