The Russian Investigative Committee reported there were 15 dead, though the Interior Ministry puts the death toll at 18, RIA Novosti reported.
"According to preliminary data, 18 people were killed and 10 bodies have been pulled out to the surface," the ministry said in a statement.
The regional Emergencies Ministry said 26 miners were working in that section of the mine when methane gas exploded at approximately 2,600 feet below ground. There were 259 total people working in the mine at the time of the explosion, RIA Novosti reported.
The Vorkutinskaya coal mine has been in operation since 1973 and produces 1.8 million tons of coal annually. The mine is owned by Severstal, one of Russia's largest steel producers.