KIEV, June 9 - At least 23 Ukrainian coal miners were rescued to safety on Monday, 40 hours after a powerful methane gas explosion rocked a coal mine, trapping 37 miners at a depth of 1,000 meters.

The office of Oleksandr Turchynov, the first deputy prime minister who oversees the rescue operation, said more coal miners might still be alive inside the mine, adding that rescue teams have been trying to reach the trap.

But what makes the rescue operation extremely difficult is that the explosion has destroyed all equipment that had been used for lifting coal miners.

“The transportation infrastructure has been completely destroyed,” Turchynov said in comments broadcast by UT-1 television on Monday. “Rescue workers had never used to work in such harsh conditions.”

The rescue operation continues as the fate of 13 coal miners was not yet clear, according to the Turchynov’s office.

At least one Ukrainian coal miner was killed when the blast occurred at the Karl Marx coal mine in the Donetsk region in eastern Ukraine at 5:00 AM on Sunday, trapping 37 coal miners at the level 1,000 meters below the surface, according to the Emergency Situations Ministry.

Some 235 rescue workers in 31 different teams have been sent to locate the missing coal miners at the coalmine over the past 40 hours, according to the ministry.

The teams have been operating 43 pieces of rescue machinery in the rescue operation, the ministry said.

The blast, and the fire, was so powerful that it had injured five workers on the surface, according to the ministry.

Ukrainian coal mines, especially those in the Donetsk region, have unusually high content of methane gas and its frequent explosions kill and injure hundreds of coal miners annually.

Ukraine produces about 80 million metric tons of coal annually, but the government has been seeking to increase the output to 100 million metric tons within years to reduce the country’s dependence on Russian natural gas imports.

Ukraine extracted 33.34 million metric tons of coal in January-May, up 3.6% year-on-year, according to the energy and fuel ministry. (sb/ez)