At least 90 people have been killed and nine are still missing after a gas explosion at a coal mine in northern China’s Shanxi province, in what state media described as the country’s worst mining disaster in 17 years.

The blast struck the Liushenyu coal mine, operated by the Tongzhou Group in Qinyuan county, at 19:29 local time on Friday while 247 workers were on duty underground, broadcaster CCTV and the Xinhua news agency reported. Twenty-seven people remained in hospital on Saturday, one in critical condition.

Most casualties were caused by inhalation of poisonous fumes, state media said. Carbon monoxide levels in the shafts had “exceeded limits”, with rescuers carrying stretchers from the site as ambulances waited.

An injured miner, Wang Yong, told state media he “smelled sulphur, the same smell you get from blasting” before seeing colleagues collapse from the fumes. “I shouted at people to run,” he said.

President Xi Jinping ordered authorities to “spare no effort” in treating the injured and conducting search and rescue operations, and called for a “thorough investigation into the cause of the accident and strict accountability in accordance with the law”. Premier Li Qiang echoed those instructions, demanding timely release of information. Executives at the company operating the mine have been detained, Xinhua reported.

The Liushenyu disaster surpasses the 53-death open-pit mine collapse in Inner Mongolia in 2023 and is the deadliest single incident since a 2009 explosion in Heilongjiang killed more than 100 miners. China has significantly reduced coal mining fatalities since the early 2000s through stricter safety regulations, though gas blasts and floods remain the largest single cause of underground deaths.