Ambulances leave?the Yanshitai Coal Mine in Wansheng district?of Southwest China's Chongqing municipality Wednesday morning. [Photo/chinanews.com]

CHONGQING -- Twenty-two people are confirmed dead after a coal mine accident on Tuesday evening in Southwest China's Chongqing Municipality, local authorities said.

Rescuers have retrieved the bodies of all the missing miners, the authorities said.

The accident happened at 5:40 pm at the Yanshitai Coal Mine in Wansheng District, according to the Chongqing Municipal Administration of Coal Mine Safety, which said it was a "gas incident."

A total of 28 miners were working down the shaft at the time of the accident, it said. Six of them managed to escape, with two injured in the process.

The coal mine belongs to the state-owned Nantong Mining Co, Ltd, which is the largest coal producer in Chongqing.