The blast happened at the Xiaojiawan mine in the city of Panzhihua at around 6:00 p.m. local time (1000 GMT) on Wednesday.

At least 28 workers were also trapped underground.

City officials said about 150 miners were working underground at the time of the explosion.

Chinese state television said rescue teams retrieved the bodies 16 miners, who died from carbon monoxide poisoning, and the other three workers died en route to hospital.

Efforts are underway to rescue the remaining miners. By Thursday morning, more than 100 people had been rescued and taken to hospital.

The mine is owned by Zhengjin Industrial and Trade Co., Ltd., whose owner has been taken into police custody for further investigation.

Mining in China has been rated one of the most dangerous industries in the world due to poor safety standards. Official figures indicate that 1,973 people died in coal mining accidents in the country in 2011.

China has about 12,000 coal mines, according to state media.

The Chinese government has shut down hundreds of mines this year as part of efforts to improve safety standards.