The accident at the Karl Marx mine in the town of Yenakiyevo in the Donetsk Region occurred at 6:00 a.m. Moscow time (02:00 a.m. GMT) on Sunday when a gas and air mixture exploded.
Ukrainian Deputy Prime Minister Alexander Turchinov said: "There was an attempt to descend into the mine using the cargo chute. During the descent attempt, voices were heard, and there is hope that they are alive."
The ventilation system is working, so the miners are able to breathe, he said.
Four of the miners who were on the surface at the time of the blast suffered injuries.
Work at the mine was suspended several days before the accident after violations of safety rules were exposed. Only miners responsible for the mine's maintenance were underground at the time of the blast.