(ECNS) -- An explosion occurred at a barbecue restaurant on Wednesday night in Xingqing District, Yinchuan City, Ningxia Hui Autonomous Region, killing 31 people and injuring 7, local authorities said Thursday.
Of the seven, one is still in critical condition, two with moderate burns, four with mild injuries.
According to witnesses at the scene, a gas tank in the barbecue restaurant on the first floor exploded, detonating the gas pipeline on the second floor.
A woman surnamed Chen told reporters who arrived at the scene that at 20:36 Beijing time, she and her mother were about 50 meters away from the barbecue restaurant when they suddenly heard a huge explosion. About five minutes later, emergency ambulances and firefighting vehicles arrived at the scene.
A waiter of a nearby hot-pot restaurant said at about 11 p.m., the fire was put out.
Local governments in Ningxia have set up teams for follow-up treatment.
The cause of the accident is under investigation.