A deputy head of a coal mine where a gas blast on Sunday killed at least three people has been taken into police custody after he confessed to having covered up the death of one miner, local police said on Thursday.

Peng Qingrui, deputy head of the Songshutan Coal Mine in Inner Mongolia, inspected the mine shaft shortly after the blast occurred and found the bodies of two miners and one miner still alive.

He admitted Wednesday night that he transported the injured miner to a hospital in neighboring Ningxia Hui Autonomous Region, police said.

Peng said the miner died on the way to hospital, according to Jiang Dongwen, a police officer with the Alxa League Public Security Bureau.

The gas explosion is believed to have occurred around 11:30 AM Sunday. Five injured miners managed to escape from the mine shaft and rescuers brought another miner to the surface later in the day.

Peng just reported the death of two miners but covered up the death of the miner he had transported to Ningxia, police said.

Four miners were still missing and their chances of survival are extremely slim as a fire is burning underground, said Li Xinsheng, who is in charge of the rescue operations.

"Rescuers have attempted to go down the shaft five times but have been forced to turn back because of the scorching blaze," said Li.

Rescuers have been trying to close the ventilation pipes to cut the oxygen supply to put the fire out. But not progress was made by press time. "It is likely to take four to five days to let the fire perish itself," said a rescuer.

Further investigation into the accident is underway.

Underground repair work that was carried out in violation of safety regulations is being blamed for the gas blast, said Wu Zhaowei, deputy head of the team for investigating the accident.

The Songshutan Coal Mine was ordered to stop operations last April. "Production activity was banned in the coal mine," said Wu. Ignoring regulations the mine managers secretly sent miners down the shaft to make repairs and install a new ventilation and drainage system, Wu said. "The coal mine managers also failed to submit their repair work plan to local production safety supervision authorities for approval," Wu said.

(Xinhua News Agency December 21, 2006)