The explosion at the Komsomolskaya mine in the arctic coal-mining town of Vorkuta, in the Komi Republic, occurred Monday evening when 277 people were working underground. Rescuers evacuated at least 250 miners, but three are still reported missing.
"Four miners have been hospitalized, one in a serious condition," the spokesman said.
Local prosecutors launched an investigation into the blast, which comes in the wake of a series of tragedies at Russian mines since the beginning of the year.
The two latest blasts, at the Yubileinaya and Ulyanovskaya mines in the Siberia's Kemerovo Region in May, killed a total of 150 people.