Four miners were killed, three more missing and five others injured in a coal mine tunnel collapse in Luntai, a county in southern Xinjiang Uygur Autonomous Region, on Tuesday afternoon.

The accident took place around 4?PM on Tuesday at Baoshan Coal Mine, some 60 km away from the county seat of Luntai, while miners were working to seal off a conflagration, said sources from the Southern Branch of Xinjiang Regional Bureau of Coal Mine Safety Supervision.

The cause of the accident is still unknown, as the toxic gas concentration in the shaft has exceeded the standard limit, preventing rescuers from going down the shaft to find out the fact, said the sources.

Being informed of the accident, workers from the Southern Branch of Xinjiang Regional Bureau of Coal Mine Safety Supervision rushed to the site of the accident to offer help in the rescue operation.

All the injured were hospitalized.

Investigation over the cause of the accident is underway.

Baoshan Coal Mine is a private coal mine capable of producing 90,000 tons of coal a year.

(Xinhua News Agency May 16, 2007)