At least 31 people were killed in an explosion that occurred on Wednesday night in a restaurant in the city of Yinchuan in northwestern China, the official Xinhua news agency reported, AFP reports.

“A liquefied gas leak (…) caused an explosion when the restaurant’s grill was being used,” the agency explained, citing the regional committee of the Communist Party of China.

Another seven people were treated, with one in “critical condition,” Xinhua reported.

According to the same source, two other victims suffered serious burns, two others suffered minor injuries, and two more were injured by broken glass.

Footage on state television CCTV showed more than a dozen firefighters battling smoke billowing from the gaping hole caused by the blast. The street, on which other food and entertainment establishments are located, was littered with garbage.

The blast occurred around 8:40 p.m. (12:40 GMT) at the Fuyang Barbecue restaurant, located in a residential area in the center of Yinchuan, the capital of Ningxia Autonomous Region.

The tragedy happened a day before the Dragon Boat Festival, a three-day celebration where many Chinese gather with family and friends.

The Ministry of Emergency Situations reported that after the explosion, local fire and rescue services sent more than 100 people and 20 pieces of equipment to the scene.

Rescue operations ended at 04:00 on Thursday (20:00 GMT on Wednesday), the ministry added.