A powerful blast ripped through a coal mine in eastern Ukraine Sunday morning, leaving four miners injured and 37 others missing.

Viktor Poltavets is the country's Coal Industry Minister.

"Repair workers were working on this shift. There were 37 people. The dispatcher told them of a gas threat and people started to leave their working positions and gathered at the mine's shaft to leave it. The explosion happened at 5 a.m."

Officials say the rescue teams heard the voices of some of the trapped miners after attempting to get to them through a damaged shaft, adding that the ventilation system in the mine was still working.

The methane explosion, one of the most powerful in the country's mining history, tore through the Karl Marx mine in the eastern city of Donetsk, trapping the miners some 1,000 meters underground.

The state-run mine, where another explosion killed seven in 1999, had been declared too dangerous to operate and the trapped miners were underground to improve safety conditions.

Ukraine has some of the world's most dangerous mines because of outdated equipment and poor safety standards.

Ukrainian Officials say that for every one million tons of coal brought to the surface in Ukraine, three miners lose their lives.