Officials said Friday that the search for 24 workers missing after a coal mine explosion won't resume for a week, apparently eliminating hopes of finding them alive.

Rescue operations at the Raspadskaya mine in western Siberia were suspended Thursday because of heavy concentrations of explosive methane and fires in the tunnels. On Friday, Emergency Situations Ministry official Pavel Plat said the methane couldn't be reduced to safe levels for at least a week.

"We simply can't let people remain in the kind of situation that has developed" in the mine, he said.

The confirmed death toll stands at 66 from the pair of explosions that rocked Russia's largest underground coal mine over the weekend. That includes 17 rescuers who were sent into the mine after the first explosion and were caught in the second blast, which was so enormous that it severely damaged buildings on the surface.

There have been no reports of contact established with any of the 24 miners still missing, who were believed to be about 450 meters underground.

Both blasts were blamed on methane, but it's not clear what set them off.

Safety regulations are often loosely observed at Russian mines, and on Thursday the federal industrial watchdog Rostekhnadzor said it was beginning unannounced spot checks at mines throughout the country.

On Friday, Kemerovo region governor Aman Tuleyev said one of the 66 people killed in the explosion was a fired mine employee whose body was found with two knives and a roll of copper wire. The man was believed to have been stealing metal items from the mine, Tuleyev was quoted as saying by the ITAR-Tass news agency.