Rescuers said 21 miners managed to escape when the blast struck -- a total of 65 miners were working underground at the time.

"We'll try our best to find the missing miners and I hope they are still alive,'' an official with the Provincial Coal Production Supervision Authority told China Daily.

The official, who declined to be identified, said rescuers were working around the clock to get the tunnel ventilated by shifting mounds of rubble dislodged by the blast, which struck the Zhujiadian Coal Mine in Zhongyang County, Shanxi Province at 4:20 pm on Wednesday.

The State Administration of Coal Production Safety Supervision Thursday sent an investigation team, headed by its deputy-administrator Wang Dexue, to the scene.

A member of staff at the Shanxi Coal Mine Production Safety Bureau said the explosion coincided with a three-day provincial coal mine safety conference, convened in Yangquan a region rich in high-quality coal.

"We are alert and most of the provincial heads have attended the event. The blast happened in the middle of the conference,'' said the official, surnamed Wang.

Coal mine accidents are a frequent hazard in the province--which holds the richest coal reserves in the country--owing to poor safety levels in respect of equipment and risk awareness among both miners and pit owners.

Many accidents have occurred at smaller privately, or collectively owned mines, some of which are unlicensed and operate without even a minimum level of safety standards.

But even State-run mines are prone to fatal accidents.

Thousands of pits deemed unsafe have been closed down in recent years, but many re-open as soon as safety inspectors’ move on to the next area.

The State Administration of Work Safety last week emphasized in a circular that relevant authorities should continuously monitor the management of coal mines, dangerous chemicals, road and water transportation.

To cut down the number of accidents, the administration highlighted the need to improve safety awareness among the miners themselves.

For those key coal mines, supervision by the administration will focus on ventilation systems and measures to prevent fires, the build-up of gas and floating coal particles, said the circular.

"The coal mines with bad safety records must stop production and shall not be allowed to re-open until their safety measures meet required standards,'' the circular was quoted as saying.

(China Daily October 25, 2002)