 A gas explosion at a barbecue restaurant on June 21 night in China's northwestern Ningxia region killed 31, state media reported. The blast in Ninhuan, capital of Ningxia, was caused by a leaking liquefied petroleum gas tank at the restaurant, the official Xinhuan news agency reported on Thursday. Video obtained by Reuters showed smoke and flames rising from the restaurant as firefighters worked to extinguish the fire. Reuters was able to locate the burning building from the various signage and features on the building and road layout as seen on file images. Seven people were still undergoing treatment for burns and cuts from broken glass as of Thursday, Xinhua said. Chinese President Xi Jinping told authorities to go all out to treat the wounded and said safety supervision in key industries and sectors should be strengthened, state broadcast CCTV reported.