Police detained Tuesday four people over a gas poisoning accident that killed six miners in north China's Inner Mongolia Autonomous Region, the local public security authority said.

Dan Hongyu, head of the Luxinju Coal Mine, He Ping and Yuan Fucheng, two deputy heads, and safety inspector Jin Xifu, were detained Tuesday afternoon and preliminarily are being held responsible for the fatal poisoning, according to Wang Gangzhu, deputy director of the public security bureau of Jungar Banner.

The bank accounts of the four have also been frozen, Wang said.

The accident happened at about 10:20 p.m. Monday in a mine of Juneng Coal Mine Co. Ltd. in Jungar Banner when at least nine miners were working underground and poisoned by an unknown gas.

The first miner was rescued at 5:25 a.m. Tuesday and the rest of them were pulled out of the pit at 6:15 a.m.. They were rushed to the hospital but died later. Three people were slightly poisoned.

Luxinju Coal Mine is a licensed, private mine with a reserve of 19.87 million tonnes.

The cause of the accident is under investigation.

All collieries in Jungar Banner were ordered to suspend operation as of Wednesday for a week for safety overhaul, the banner's government said Tuesday afternoon.

The government of Ordos City, which administrates Jungar Banner, also imposed a month-long work safety examination Tuesday in an effort to rid safety risks.

(Xinhua News Agency March 10, 2009)