Sixty-nine miners have been safely evacuated to the surface.

Rescue efforts so far have been reportedly hampered by the high levels of methane which has to be diffused to prevent further explosions.

The BBC said the miners died of smoke inhalation, though it was unclear what the source of the smoke was.

Mining giant Siberian Coal Energy has established a regional emergency center to continue the rescue and gas extraction operations.

The mine is located in the Kuzbass coal basin of Russia’s Kemerovo region.