Officials from the Ukrainian government's Donetsk regional administration said late on March 4 that 33 miners were killed by an explosion in a coal mine earlier in the day.
However, those officials have been unable to reach the mine themselves because it is in an area that is under the control of Russian-backed separatists.
Rebels in the self-declared separatist administration said late on March 4 that only 24 deaths were confirmed and that nine miners were still missing.
The Donetsk administration, now based in the government-held port city of Mariupol, said it received reports that the bodies of 17 miners were retrieved from the Zasyadko mine.
It said 16 others were found and would soon be brought to the surface.
Authorities in Kyiv attempted earlier to send rescue teams to the mine in eastern Ukraine.
But Ukrainian Prime Minister Arseniy Yatsenyuk said the separatists refused to allow rescue teams into the area.
"That is why I am publicly calling on the Russian Federation -- order these rascals to allow our mine-rescue brigades to save the lives of miners," Yatsenyuk said.
Eastern Ukraine has been devastated by a conflict between the Russian-backed rebels and government forces that has killed more than 6,000 people since April.
Fighting has continued despite an EU-brokered cease-fire deal that was signed in Minsk on February 12.
With reporting by AP, TASS, and Interfax