The death toll in China’s worst mine accident in nearly three years has risen to 37 as high temperatures and dangerous carbon monoxide levels hampered rescue work Friday for 10 others still trapped.

Police detained the owners of the Xiaojiawan coal mine following Wednesday evening’s blast in coal-rich Panzhihua city in the southwestern province of Sichuan. 

There were 154 miners working at the mine when the explosion occurred, and 107 survivors have been pulled to the surface, the State Administration of Work Safety said in a statement.

It is China’s deadliest mine accident since 108 were killed in an explosion in a mine in Heilongjiang province in November 2009. 

The official Xinhua News Agency said the rescue work was dangerous because of high temperatures in the mine and dense carbon monoxide that meant only paramedics wearing masks were able to enter the shaft.

Xinhua quoted one miner, Xu Changyong, as saying he heard the explosion and then ash started coming out of his air compressor before he scrambled out of the mine. Of the miners who made it to the surface, 50 are suffering from carbon monoxide poisoning and seven are in critical condition, Xinhua said.

The mine is owned by Zhengjin Industry and Trade Co. Ltd. and the owners were in police custody for investigation, the Panzhihua city government said in a statement posted on its official microblogging site.

Coal mine accidents are common in China, where work safety rules are often ignored.

Last year, 1,973 miners were killed in coal mine accidents in the country, but that was down 19 percent from the previous year as authorities continue to beef up safety measures.

The State Administration of Work Safety said last week that it planned to close more than 600 small coal mines — considered more dangerous than larger mines — this year to further reduce fatalities.

- AP