GUIYANG - Seven people have been confirmed dead and two others injured in a coal mine gas blast in southwest China's Guizhou province, local authorities said on Friday.

Fifty-seven miners were working underground when the explosion occurred around 6 am at the Shibanpo coal mine in Chayuan township, Jinsha county, sources with the county government said.

Fifty of them were lifted out after the blast, including two injured people who have been sent to a local hospital. Their conditions are not immediately known.

An initial investigation showed that the explosion was triggered by underground blasting, which then ignited gas stored in a worked-out area.

The mine has an annual capacity of 300,000 tonnes of coal.