URUMQI - Four people were killed and another was seriously injured on Thursday in a gas explosion that occurred in a coal mine in northwest China's Xinjiang Uygur autonomous region.

The accident took place at 10:50 am in a mineshaft in the Xinyuan Coal Mine, which is located in Barkol county. Twelve workers were in the mineshaft when the explosion occurred, according to a spokesman from the region's coal safety supervision bureau.

Rescuers managed to pull seven of the workers out of the shaft, with one injured worker sent to a local hospital for treatment.

The Xinyuan Coal Mine was built in 1997 and has an annual coal production volume of 90,000 tonnes.

The cause of the explosion is under investigation.