Russian emergency workers started on Saturday to pump water into the west Siberian mine where at least 66 people died in an accident last week, a regional emergencies ministry official said.
Twenty-four people are still missing underground but search operations were halted on Thursday due to the threat of high concentrations of methane gas causing further explosions.
"At 6.45 a.m. Moscow time the pumping of water and refrigeration agents began," Kemerovo Region Emergency Situations Minister Yerem Arutyunyan said, adding that ventilation fans had also been restarted.
The Raspadskaya mine near the Kemerovo Region city of Mezhdurechensk was hit by two explosions about four hours apart on the night of May 8-9. The second, more powerful explosion destroyed the main ventilation shaft and killed a number of rescuers who had gone underground following the first blast.
The work to make the mine safe for rescuers to go back into the tunnels, which involves flooding some dead-end sections to eliminate smoldering fires and reduce methane levels, is expected to take about a week.
Officials said emergency workers would only return underground when tests showed it was safe to do so. An emergencies spokesman said the switch from search-and-rescue operations had been approved by experts after careful analysis of the situation.
Tensions rose in Mezhdurechensk on Friday as miners and their relatives protested against wage levels and working practices at the mine, which is Russia's largest underground coalmine. The owners have closed the territory of the mine to anyone not involved in the emergency response.
KEMEROVO, May 15 (RIA Novosti)
