Rescue workers emerge from the Tunlan Coal Mine in Gujiao, in Chinas Shanxi province, Feb 22, 2009. — AP

GUJIAO, China Rescuers ended efforts Monday to find more survivors at a northern China coal mine where at least 74 people were killed the day before in underground explosions in the countrys deadliest mine disaster in a year.

Of the more than 300 survivors of the accident at the Tunlan mine, 114 remained in the hospital, five of them in critical condition, said an official with the Shanxi provincial government spokesmans office, speaking on condition of anonymity, citing policy.

The spokesman said the cause of the blast remains under investigation.

The mines manager, chief safety officer and chief engineer have been removed from their posts as part of the investigation, the official Xinhua News Agency reported. Xinhua did not identify the men by name or give other details.

A statement posted on the provincial government Web site said final checks on the mine were being conducted.

The next step is to double-check at the bottom of the well...to treat the injured and properly save all the data files in preparation for the investigation, the statement said.

A half-dozen ambulances stood parked Monday and a pair of policemen guarded the gates into the shaft of the mine in Gujiao near the provincial capital of Taiyuan — in contrast to the frenzied rescue operation that followed Sundays pre-dawn explosions. Then, rescuers wearing headlamps and oxygen backpacks carried dozens of miners to safety.

But on Monday, cleaners simply swept up around the two stone lions marking the entrance to the mine.

The mine belonging to the state-run Shanxi Coking Group, Chinas largest producer of coking coal, and had boasted an excellent safety record. The company is the worlds second-largest producer of coking coal, used in the production of steel, with sales revenues of more than 37 billion yuan in 2007.

One survivor, Xue Huancheng, was quoted by Xinhua on Sunday as saying he had been ordered to flee because the ventilation system had broken down, possibly triggering a safety alarm.

Xie, like most of the other survivors, suffered carbon monoxide poisoning, Xinhua said, citing doctors. Exposure to carbon monoxide — an odorless, colorless gas — can cause headaches, dizziness, nausea and can lead to death.

Most coal mine explosions are sparked by the accumulation of unventilated coal gas.

Xinhua said the Tunlan Coal Mine had among the best facilities of any mine in China and no major accidents had occurred there in five years.

The death toll was the highest from a China coal mine accident since Dec 2007, when gas exploded in an unventilated tunnel in Linfen city, also in Shanxi province, killing 105 miners.

Beijing has promised for years to improve mine safety, and more than 1,000 dangerous small mines were closed last year. But Chinas mining industry remains the worlds deadliest.

About 3,200 people died in coal mine accidents last year, a 15 per cent decline from the previous year.