At least six rescue workers have been killed when an explosion struck the mine where they were searching for 26 miners who have been missing since another explosion earlier in the week.
Officials said the six rescuers died on February 27 at the Severnaya coal mine near the Far Northern city of Vorkutsk. Four miners were killed and nine injured in an explosion and fire at the mine on February 25.
Rescue workers have been working since then to locate the 26 missing men, who have not been heard from since the original explosion.
All rescue work was halted following the most recent explosion at the accident-prone mine.
A spokesman for Russia's Emergency Situations Ministry said all the killed rescue workers would be given state medals.
Earlier, a spokeswoman for the company that runs the mine said rescue efforts had been hampered by high methane levels inside the mine.