Only 93 people have been rescued so far of the 203 miners that had been underground at the time of the blast in the Ulyanovskaya mine in Novokuznetsk, the largest coal producing center in the Kemerovo Region.
A technical watchdog said the condition of equipment was not a cause of the blast.
"The Federal Service for the Oversight of the Environment, Technology and Nuclear Management is considering two versions of what might have caused the accident in the Ulyanovskaya mine in the Kemerovo Region - subsidence and human factor. According to preliminary data, the condition of equipment could not have caused the methane-air mixture to explode," the service said.
Over 500 rescuers are working at the scene searching for five miners still missing and taking the bodies of those killed to the surface, the press service of the Ministry of Emergency Situations said.