TONGCHUAN, Nov 28: A gas explosion ripped through a coal mine in north China's Shaanxi province on Sunday, trapping 166 miners in what threatens to be the worst disaster to hit the world's biggest coal producer in recent years.

A total of 293 miners were in the Chenjiashan coal mine in Tongchuan city at 7:10 am (2310 GMT Saturday) when the blast occurred. Some 123 escaped or were rescued soon after and four more were hauled out alive 10 hours later.

"There are now 166 trapped," an official from the Shaanxi provincial coal mine safety supervision bureau surnamed Duan told AFP. The State Administration of Coal Mine Saftey said in a statement that 41 miners were in hospital, five of them in serious condition.

The explosion happened in a pit some eight kilometres from the entrance to the shaft and the trapped workers were located deep underground, the Xinhua news agency said. It was impossible to tell whether they were still alive, local officials said.

"We're still trying to rescue the miners. We've managed to save a few people so far," said Duan. "We haven't seen any bodies yet." President Hu Jintao had urged the local government and departments concerned to "take substantial steps and spare no efforts" to save the trapped miners, Xinhua said.

Seven local teams of rescuers were frantically trying to reach the miners and an additional 10 teams from nearby mining jurisdictions had been called to assist, it said. -AFP