Dozens of people are missing after a fire filled a mine with smoke in Siberia, leaving at least 11 dead.
Disaster struck on Thursday morning when coal dust in a ventilation shaft caught light, according to the Russian state news agency Tass.
About 285 people were in the mine at the time, with the majority escaping.
But at least 35 were still underground when it was decided to pause the search for survivors, due to the risk of an explosion.
Local governor Sergei Tsivilev said in a video on Telegram that dangerously high levels of methane had been detected in the Listvyazhnaya mine, in the Kemerovo region, some 3,500km (2,175 miles) east of Moscow.
“Work will resume as soon as the gas concentration decreases to a safe level,” he said, according to AFP news agency.
Mr Tsivilev earlier said they had lost contact with the missing miners as the underground communications system was not working.
A total of 49 people were taken to hospital with injuries, officials said, some of them with smoke poisoning. Four were said to be in a critical condition. Eleven people are known to have died.
Russian President Vladimir Putin said he hoped “(they) will be able to save as many people as possible”, describing the loss of life as “a great tragedy”.
This is not the first accident at the mine, according to local media, with a methane gas explosion killing 13 in 2004. More widely, accidents in Russian mines are not uncommon.
In 2016, authorities assessed the safety of the country’s 58 coal mines and declared 34% of them potentially unsafe. The list did not include the Listvyazhnaya mine at the time.