Investigators say the explosion ripped through the Zasyadko mine in the eastern Donetsk region, about 1,000 meters underground.
Initially close to 500 miners were trapped, but most have been brought to safety. Nearly two dozen required emergency treatment at a local hospital, many with burn injuries.
Ukraine's Emergency Situations Ministry has told VOA that for many help has come to late. Duty officer Vladimir Gembovich says they have recovered the remains of dozens of miners. His ministry has been flooded by phone calls from relatives desperate for news of their loved one. Shocked family members gathered by the mine since Sunday morning.
Gembovich says the investigation into the cause of the blast will try to determine what triggered the incident.
"They say it was an explosion of methane [gas] mixed with air," Gembovich said. "But I think an investigation will be carried out afterwards and it will clarify everything."
Experts say the Zasyadko mine, one of Ukraine's largest, employs some 10,000 people and produces up to 10,000 tons of coal every day.
Since 1999 more than 140 miners have lost their lives in accidents at the facility, which has gained a reputation as one of the most dangerous in the country.
Among the most serious accidents was a gas leak in September 2006 that killed 13 miners and made dozens more sick. And, in 1999 an explosion there claimed 50 lives, while in 2001 another blast claimed 55 lives.
Russian news reports say that on Saturday in the Lenin Mine, also in Donetsk region, one miner died after a section of tunnel collapsed. It comes amid a debate on the future of mining in Ukraine, where a lack of modern equipment has made the mines among the world's most dangerous.
