At least 31 people have been killed and seven injured on Wednesday as the result of a gas explosion at a restaurant in northwestern China. The blast was caused by a leaking liquefied petroleum gas tank.

“A leak of liquefied petroleum gas … caused an explosion during the operation of a barbecue restaurant,” state news agency Xinhua said on Wednesday.
The owner, shareholders, and staff of the restaurant were among the nine people who were detained by police after the explosion.

According to media accounts, the BBQ restaurant in Yinchuan, the region’s capital, is very popular among locals. High school students and pensioners were among those killed in the explosion, which occurred during the busiest dining hours.