The explosion happened at about 11:30 a.m. Monday (11.30 p.m. Sunday ET) at the privately-owned Jinshangou Coal Mine in Laisu town in Chongqing’s Yongchuan district, Xinhua reported.
In the early hours of Wednesday, the bodies of 15 missing miners were found, taking the total death toll to 33.
Two of the 35 miners underground at the time managed to escape, according to a statement posted to the Chongqing press office’s official Weibo social media page.
More than 200 rescue workers, including firefighters, police and rescue specialists were sent to the site to try to locate the missing miners, Xinhua reported.
Chongqing’s coal mine safety inspection bureau has ordered all coal mines in the municipality to halt production pending safety inspections, it reported. The cause of the explosion is under investigation, city officials said.
Mining accidents are not uncommon in China. According to the State Administration of Work Safety, 598 people died in mining accidents last year.
In March, 12 people were killed by a gas leak in a mine in the northeastern province of Jilin, while in January, four miners were rescued after 36 days of being trapped underground. At least one miner died in that accident.