Seventeen coal miners have died after being trapped by a gas explosion in north-western China, state media reported.

The miners were trapped on Saturday by the explosion at a mine 70 miles from Urumqi, the capital of the Xinjiang region, the Xinhua News Agency said.

The cause of the incident is under investigation.

China has the world's deadliest mines, although the safety record has improved as regulators strengthen enforcement of safety rules.

Xinhua said the pit where the explosion occurred is mined by Dahuangshan Yuxin Coal Mining Co Ltd, owned by the sixth agricultural division of the Xinjiang Production and Construction Corps.

It is a paramilitary organisation that was revived by the central government in the 1980s to aid the region's construction and development.

Three other people working inside the mine were rescued earlier.