"There is hope they are alive," he said, 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 around 5 a.m., trapping the miners some 3,300 feet underground, officials said.
The injured workers - three of them women - were hospitalized with severe burns, said Maryna Nikitina, a spokeswoman for Ukraine's industrial safety watchdog agency.
The explosion damaged two shafts and destroyed several buildings above ground, according to TV reports.
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, officials said.
Ukraine has some of the world's most dangerous mines because of outdated equipment and poor safety standards. Since the 1991 Soviet collapse, more than 4,800 miners in Ukraine have been killed. Officials say that for every 1 million tons of coal brought to the surface in Ukraine, three miners lose their lives.
Coal-rich Donetsk is about 400 miles southeast of the capital, Kiev.