Coal dust caught fire in a ventilation shaft at the Listvyazhnaya mine in the Kemerovo region, which was covered with snow and ice, causing the mine to smoke, the TASS news agency cited local emergency services as saying.
Regional governor Sergei Tsivilev said 11 people had died and 46 were still underground. Dozens of others are being treated at the hospital, at least some of them suffering from smoke poisoning. Four people are in critical condition.
Rescue workers and ambulances were able to reach the mine in the video, with police gathering outside as it snowed in an area about 3,500 kilometers (2,175 miles) east of Moscow.
The emergency department said about 285 people were inside the mine when smoke spread through the ventilation shaft. Authorities said at least 239 were on the ground. They did not say what caused the smoke.
Tsivilev said there is no longer thick smoke in the mine, which still has electricity and ventilation, but that contact has been lost with some people deep underground.
“There is no thick smoke at the moment, so we hope that there is no fire,” Tsivilev said in video comments shared on his Telegram channel. “We don’t have a line of communication with these people, the underground communication system doesn’t work.”
The regional branch of Russia’s Investigative Committee said it had opened a criminal case for negligence that resulted in the death of a person.
“According to preliminary data, some workers suffered from smoke poisoning. The number of victims is being determined,” it said in an earlier statement.
The mine is part of SDS-Holding, which is owned by the privately held Siberian Business Union. The union was not immediately available for comment.