Chinese police arrested four people on Saturday linked to a restaurant explosion that killed dozens, state media reported.
At least 31 people were killed and seven others injured when a gas explosion ripped through a barbecue restaurant in the northwestern city of Yinchuan on Wednesday.
It happened on the eve of the three-day Dragon Boat Festival holiday when many in China go out and socialize with friends.
The suspects included the restaurant owner, two shareholders and the manager, state news agency Xinhua reported.
They were arrested for allegedly "causing a serious accident through negligence" and a criminal investigation was under way, Xinhua said.
The local public security bureau had frozen the assets of nine individuals, including the four arrested, it added.
Chinese President Xi Jinping had "demanded all-out efforts in treating the wounded and the strengthening of safety supervision and management in key industries and fields to effectively protect people's lives and property," Xinhua said Thursday.
Explosions and other deadly incidents are relatively common in China, where building codes are often poorly enforced and widespread unauthorized construction can make it hard for people to flee burning structures.
At least 17 people died in a fire at a restaurant in the northeastern city of Changchun in September 2022, according to statements given at the time by local authorities.
In January of the same year, an explosion triggered by a suspected gas leak brought down a building in the city of Chongqing, killing more than a dozen people.
And 25 people were killed in a gas blast that ripped through a residential compound in Hubei province's Shiyan in June 2021, also striking a busy two-story building packed with shoppers.