Officials said 217 people were working in the Yubileinaya mine at the time of the blast; 28 of them were in the immediate vicinity of the blast and the rest were in other parts of the mine.
 
An explosion at another mine in the region in March killed 108 people.
 
That was the deadliest accident in more than 60 years in Russia's mines, many of which fell into disrepair when government subsidies dried up after the 1991 collapse of the Soviet Union.