The death toll from a gas explosion at a Chinese coal mine has risen to 43, state media reported Saturday, with three miners still remaining underground.

Yang Dongliang, head of the State Administration of Work Safety (SAWS), said the number of deaths had increased and that rescuers were looking for the three trapped miners, the official Xinhua news agency reported.

The explosion occurred late Wednesday at Xiaojiawan mine in southwest China's Sichuan province and marked the latest in a string of fatal incidents for an industry known for poor safety.

The death toll matches that from a blast at a mine in November last year in southwestern Yunnan province.

China's mines are among the world's deadliest due to lax regulation, corruption and inefficiency. Accidents are common because safety is often neglected by bosses seeking quick profits.

The latest official figures show 1,973 people died in coal mining accidents in China in 2011, a 19 percent fall on the previous year, though labour rights groups say the actual death toll is likely to be much higher.

Authorities ordered that the Xiaojiawan mine be shut and fined the company operating it five million yuan ($800,000), while 19 people were sent to face legal action, SAWS investigators said in a report earlier.

They blamed the accident, estimated to have cost 40 million yuan ($6 million) in economic losses, on illegal operation and inadequate safety policies.

Separately, China National Radio reported that Zhang Yan, the mayor of Panzhihua city in Sichuan where the mine is located, bowed and apologized Saturday to family members of the dead at the mine.