Cooking gas caused a massive explosion at a barbecue restaurant in northwestern China, killing 31 people and injuring seven others during national celebrations on the eve of a long holiday weekend, authorities said on Thursday.

The blast tore through the restaurant at around 8.40 pm on Wednesday on a busy street in Yinchuan, the capital of the traditionally Muslim Ningxia Hui Autonomous Region, as people gathered ahead of the Dragon Boat Festival, the official Xinhua News Agency said.