Beijing: At least 31 people died and seven others were hurt as a gas exploded at a barbecue restaurant in China's  Yinchuan city on Wednesday, media reports said.

The explosion was caused by a leak of a liquified gas tank inside the restaurant, and took place around 8:40 p.m., according to state broadcaster CCTV as quoted by CNN.

The condition of one of the injured persons in the incident is said to be critical.

The other six persons are treated for minor injuries, burns and glass cuts in the hospital where they were taken for treatment.

Local fire authorities sent 20 vehicles and more than 100 personnel to the scene, with search and rescue operations lasting until 4 a.m. Thursday, according to state media as quoted by CNN.

Police have detained nine people and frozen their assets, including the restaurant’s manager, employees and shareholders, local officials were quoted as saying by CNN.