Death toll rose to 31 and?one miner?remains missing in a coal mine gas explosion in Yan'an City, northwest China's Shaanxi Province, with four more bodies recovered on Monday and Tuesday, according to the rescue headquarters.

The gas blast happened at 4:20 PM Saturday in Wayaobao Township Coal Mine in Zichang County of Yan'an when 39 miners were working underground. Seven miners managed to escape to the ground.

Six officials, all shareholders and managing personnel of the mine, were arrested on criminal charges, according to a local police source. Officers are hunting a seventh official who fled after the blast.

Mayor of Yan'an Chen Qiang said a safety check in March revealed there was bad ventilation in the tunnel of the mine. He added that bosses were ordered to improve it at the time.

Though an investigation into the cause is still being under way, poor ventilation might have caused gas to build up and explode, coal mine safety experts said.

Chen Deming, governor of Shaanxi Province, went to the site on Sunday morning and said that the local administration department would also be investigated to see if it bore any responsibility for the tragedy.

In a separate accident on Sunday evening at a gold mine in southern Shaanxi, five people were injured and 17 were left missing, according to Wei Zengjun, mayor of Shanluo, yesterday.

A storage pond dam holding more than 1 million cubic meters of gold pulp suddenly broke and the pulp rushed out, destroying 40 local farmers' houses next to the dam, the mayor said.

"Among the 17 missing people, nine are female and eight male, and the five injured, four male and one female, were sent to hospital and are in stable conditions," said Mao Quanbo, an official in Shangluo's Zhen'an County where the gold enterprise is located.

About 130 families, whose properties were also at risk from the pulp, were moved to a safe area yesterday.

Rescuers were also trying to locate those missing after the accident.

(Xinhua News Agency, China Daily May 2, 2006)