Liang Jianwei, who was working near the site of the explosion, told China Daily on Sunday that many miners collapsed after inhaling toxic gas. As he evacuated on Friday, it took him about two hours to reach safety, he said.

"One by one, the miners who evacuated with me soon started to feel dizzy, so I immediately activated my portable self-rescue device, which helped me breathe. I also tried to open all the ventilation vaults in the thick dust along the way to let air in. We could see many people had already collapsed in the main shafts," said the 54-year-old, who was being treated at Qinyuan People's Hospital.

According to public information, the privately owned Liushenyu mine was listed in 2024 by the National Mine Safety Administration as a "severe safety hazard for high gas emissions". Regulations require safety management standards equivalent to those for high-gas mines, including strengthened outburst prevention measures, increased monitoring frequency and upgraded emergency response plans.

As a major comprehensive energy base in the country, Shanxi has abundant coal resources. According to the provincial government, between 2021 and 2025, daily coal production in Shanxi remained stable at over 3.5 million metric tons. Total raw coal output reached approximately 6.5 billion tons, accounting for nearly 30 percent of the national total.

The province has sent 755 rescuers and medical personnel to the site, while the Ministry of Emergency Management sent six national mine emergency rescue teams, totaling 345 people, to assist.

Guang Xinhai, captain of the Shanxi Huayang mine rescue team of the National Mine Emergency Rescue system, said on Sunday that the mission remained difficult due to cave-ins and flooding in the tunnels.

"We will not give up hope, and we will make every possible effort while ensuring the safety of team members," Guang said. "We plan to screen the entire mine by this afternoon."

Officials said toxic and harmful gases in the mine shaft had exceeded safe limits, raising the risk of secondary disasters.

Rescue plans provided by the Liushenyu coal mine were also found to be inconsistent with the actual underground layout, complicating search and rescue operations, China Emergency Management News reported.

According to the on-site command center, the explosion occurred 300 meters below the surface, and three tunnels, each about one kilometer long, were believed to be where the missing workers might be. Some underground passages have been reduced to rubble or flooded, making access impossible for rescuers, and it was believed that the missing were trapped in these areas, the report said.

To ensure medical care for the injured miners, the National Health Commission said on Saturday that it has organized health officials and multidisciplinary experts to guide treatment efforts.