There were 168 workers in the Ulyanovskaya mine when the blast occurred, and 21 were evacuated safely within about an hour, Emergency Situations Ministry spokeswoman Veronika Smolskaya said. It was not immediately clear whether the others were in danger.
Rescuers were continuing to try to evacuate workers from the mine, which is located in Novokuznetsk in the Kemerovo region in a coal-rich part of central Siberia called the Kuzbass. Rescue teams were dispatched from Novokuznetsk and the nearby city of Kemerovo.
Twelve mine rescue teams were involved, said Valery Korchagin, spokesman for the regional branch of the Emergency Situations Ministry. He said on Vesti-24 television that people were being led out of the mine.
The Ulyanovskaya mine, managed by the company Yuzhkuzbassugol, opened in 2002 and produces 3 million metric tons of coal a year, according to the RIA-Novosti news agency. Novokuznetsk is about 3,000 kilometers, or 1,850 miles, east of Moscow.
Accidents are common in the Russian coal industry. A methane blast at a different mine in Novokuznetsk killed 47 workers in 2004, reports AP.