Russian media are reporting that the death toll from an accident in a Siberian coal mine has risen to at least 52. Authorities believe a gas explosion likely occurred.
The accident happened in the Kemerovo region on Thursday.
Local authorities say 285 workers were in the mine at the time. More than 200 managed to escape.
Media reports say six rescue workers are among the victims. About 40 people had been trapped in the mine but local news agencies said there was no chance of finding any survivors.
They also reported investigators believe there was a methane explosion. Dozens of people have been treated in hospital.
Kemerovo, located roughly 3,500 kilometers east of Moscow, is known as a coal-producing region. Fatal accidents have occurred there in the past.
Local media say the Investigative Committee has launched a criminal case on charges of violating safety regulations.
President Vladimir Putin ordered the government to offer all necessary assistance to those injured.