At least 11 people have died in an accident at a coal mine in Russia’s Siberia, as emergency workers try to rescue dozens more miners who are still trapped deep underground.

Coal dust caught fire in a ventilation shaft in the Listvyazhnaya mine in the snowbound Kemerovo region on Thursday, filling the mine with smoke, the TASS news agency reported, citing local emergency services.

Eleven people were found dead, Regional Governor Sergei Tsivilev said, and 46 were still underground.

Dozens of others were being treated in hospital, at least some of them with smoke poisoning.

Four were in a critical condition.

Rescue workers and ambulances could be seen arriving at the mine’s compound in video footage, with police huddled outside as it snowed in the region roughly 3500 kilometres east of Moscow.

Some 285 people were inside the mine when smoke spread through the ventilation shaft, the emergency ministry said.

At least 239 made it above ground, authorities said. They did not say what had caused the smoke.

Mr Tsivilev said there was no longer heavy smoke in the mine, where there was still electricity and ventilation, but that contact had been lost with some people deep underground.

“For now there is no heavy smoke, so we hope that there is no fire,” Mr Tsivilev said in video comments shared on his Telegram channel.

“We have no communication lines with these people, the underground communications system is not working.”

The regional branch of Russia’s Investigative Committee said it had opened a criminal case into negligence that had caused deaths.

“According to preliminary data, a number of workers suffered from smoke poisoning. The number of victims is being specified,” it said in an earlier statement.

-Reuters