A sudden gas outburst in an illegal coal mine in Sichuan Province has killed two miners and injured three others, said local officials on Saturday.

Seven people were in the pit when the accident happened at 11:20 p.m. Friday in Xuanhan County, Dazhou City. Three escaped with injuries, while four others were trapped underground, said the county's publicity officials.

As of midday Saturday, rescuers had retrieved two bodies and were continuing to search for the missing two. The three injured are in hospital.

The cause of the accident is still under investigation.