At least seven workers were killed in a coal mine gas leak in southwest China's Guizhou Province Thursday, local authorities said.

The accident took place at about 3:30 p.m. at the Feitian Coal Mine in Zhijin County, a spokesman with the Guizhou Provincial Work Safety Administration said.

Sixteen miners were lifted above ground, but two had died and five others died en route to hospital, the spokesman said.

It was not immediately known how many miners were working underground when the accident happened.

A rescue operation is continuing, the spokesman said.