Chinese state media says the number of dead in the country's worst mine accident in recent years has risen to 43, with three miners still trapped underground.
About 150 miners were in the Xiaojiawan coal mine in Sichuan province when there was a gas explosion last Wednesday.
Fifty of the survivors are suffering from carbon monoxide poisoning and another seven are reported to be in critical condition.
The BBC reports the mine owners have been detained pending the outcome of an investigation.
Accidents are frequent in China's mining industry, which is criticised for poor safety standards.
Official figures show that 1973 people died in coal mining accidents in the country last year.
