Twenty-two people were killed in an accident at a coal mine in the southwest Chinese city of Chongqing on Tuesday, state media reported.

The accident at the Yanshitai coal mine in Chongqing municipality's Wansheng district occurred at around 5.40pm and was described as a "gas incident" by local authorities, official news agency Xinhua said.

Rescuers have recovered the bodies of all the missing miners, the news agency reported, citing local authorities.

Six of the 28 miners who were working in the shaft at the time of the incident managed to escape, Xinhua said.

The coal mine is owned by state-owned Nantong Mining Company, Xinhua reported.

Mining accidents are common in China, the world's largest consumer of coal, where mine operators often skirt safety regulations.

The accident comes after 20 people died in April when a coal mine in China's southwest Yunnan province suddenly flooded, leaving miners trapped.

Last year, China recorded 589 mining-related accidents, leaving 1,049 people dead or missing, according to the government. But both the number of accidents and fatalities were down more than 24 percent from 2012.