Nine miners were feared trapped after an explosion Monday at their mine in the Komi region in Russia's Far North, the emergencies ministry said.
A total of 259 miners were working underground when the explosion went off at the Vorkutinskaya mine, an emergencies ministry spokeswoman told AFP.
Two hundred and fifty of them made it back to the surface but nine were still trapped underground. The nine miners are believed to be alive, the spokeswoman said.
Initial reports had said around two dozen miners were working in the shaft where the explosion took place.
Eight of the 18 miners originally feared missing had been rescued by salvage workers at the scene, according to the emergencies ministry.
The explosion is believed to have been caused by methane, and rescue teams are already on the site, the emergencies ministry added.
The mine in the northern city of Vorkuta is part of the coal mining division of the Russian steel-making giant Severstal whose mills it provides with hard coking coal concentrate.
It has been working since 1973 with an output of 1.8 million tonnes of coal a year and its reserves of coal are estimated at 40 million tonnes.
Deadly blasts -- usually caused by a build-up in methane gas -- remain a frequent occurence in the coal mining industry in Russia despite recent drives to improve safety.
According to its website, in 2011 the Vorkutinskaya mine won a corporate award for "worthy working conditions -- the basis for respect in the work force".
In 2010, 68 people were killed in twin methane blasts at Russia's biggest underground coal mine, the Raspadskaya mine in the Kemerovo region of Siberia.