At least 31 people have been killed when an explosion ripped through a restaurant in the northwestern Chinese city of Yinchuan, state media reported.
"A leak of liquefied petroleum gas... caused an explosion during the operation of a barbecue restaurant," state news agency Xinhua said of the Wednesday evening blast, adding that seven more people were "receiving all-out rescue treatment".
Following the explosion, police held nine people, one of whom was the restaurant owner.
"In accordance with the law, public security organs have held nine people, including the barbecue restaurant owner, shareholders and staff... and frozen their assets," state broadcaster CCTV said, citing the regional Communist Party committee.
The blast tore through the restaurant on Wednesday evening 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.
The explosion left many people unconscious and they needed to be carried out of the shop, according to the online news site The Paper, which quoted a member of the search and rescue team. Victims included elderly people and high school students, it added.
An hour before the explosion, employees noticed the smell of cooking gas and discovered that a gas tank valve was broken, according to Xinhua. The blast occurred while an employee was replacing the valve.
Chinese President Xi Jinping demanded urgent medical care for the injured and a safety overhaul after the explosion, Xinhua said. He urged efforts to quickly determine the cause of the accident and hold people accountable under the law.
Xi also said all regions and related departments should address "all types of risks and hidden dangers" and launch campaigns to promote workplace safety.
The incident happened at an outlet of Fuyang Barbecue, a chain restaurant in Yinchuan popular for its grilled skewers and stir-fried dishes, The Paper said. The two-floor restaurant could seat 20 people on the ground floor and offered private dining rooms on the second floor where customers could also sing karaoke.
A staff member in the emergency clinic at the General Hospital of Ningxia Medical University confirmed to the AP news agency on the phone that some of the injured were receiving treatment at the hospital, but said she was not authorised to talk to media and declined to provide her name.
The Paper cited a woman identified only by her surname Chen saying she had been about 50 meters (164 feet) from the restaurant when she heard the explosion. She described seeing two waiters emerge from the restaurant afterward, one of whom collapsed immediately, while thick smoke billowed from the restaurant and a strong smell of cooking gas permeated the area.
The central government's Ministry of Emergency Management said on social media that search and rescue work at the restaurant was completed early on Thursday morning and investigators were working to determine the cause of the blast.
