At least 11 miners died as a result of the blaze and 37 remain trapped at the Listvyazhnaya mine in the East of Russia, the Governor of the Russian region of Kuzbass Sergey Civilev said.
The fire and smoke reportedly broke out in the ventilation drift of the mine at a depth of 250 meters on Thursday night. The cause of the explosion has not yet been ascertained.
"According to preliminary data, the version of equipment malfunction and natural causes came out on top," the Russian news agency Interfax said.
The police will check the mine for violations of safety requirements, which inadvertently led to the death of personnel. A helicopter flew to the scene to pick up the victims and the evacuation continues as an investigation team is working on the spot.
According to the administration of the mine, 236 miners of 285 have been evacuated as the whereabouts of 37 people were still unknown. Some sources said that several people among the trapped miners might be killed.
The local medical service reported that five victims are in serious condition, the remaining 36 people hospitalized are in a state of moderate severity.