Investigation of a gas blast that claimed six lives in a coal mine in Inner Mongolia Autonomous Region, north China, on Sunday was still underway, according to local coal mine safety watchdog on Friday.

The accident happened at about 8 AM on Sunday in the Shenghuo Coal Mine, a town-owned coal mining unit in Hulun Buir, killing six miners who were said to be carrying out technical upgrading underground, said an official with the Inner Mongolia Autonomous Regional Bureau of Coal Mine Safety.

The authorities of the coal mine first managed to organize rescue operation on their own. Three of the rescuers were slightly poisoned by carbon monoxide in the process of rescue operation.

The poisoned rescuers were being treated in a local hospital.

The regional coal mine authorities received report on the accident on Monday and immediately sent rescuers to the accident site.

Shenghuo coal mine has an annually production capacity of 60,000 tons.

(Xinhua News Agency April 6, 2007)