"Eighty people died, and the fate of another 20 is not known. Sixty-six bodies have been retrieved, and 42 of them identified," he said.
The explosion early on Sunday in the Zasyadko coalmine in the Donetsk Region caused a fire to rage through the mine. A total of 457 miners were underground at the time, and 357 have since been brought out alive.
"There is smoke in the blast area. The temperature has dropped to 50 degrees C (122 degrees F). We hope the fire will soon be extinguished," Klyuyev said.
He said a new explosion is unlikely. "Rescue workers have done everything to prevent this."
Prosecutors said earlier on Monday that the criminal investigation into the cause of the blast would look into whether breaches in health and safety procedures had led to the deaths of the miners, but that at present there was no "concrete evidence" of safety violations.