Rescuers tunnelling through a blocked shaft on Monday retrieved alive two of 37 miners missing after a gas explosion at a pit in Ukraine's Donbass coalfield, officials said.

The regional mine inspectorate said the body of a third miner was also found about 700 metres (2,300 feet) below the surface at the Karl Marx mine northeast of the regional centre Donetsk.

The inspectorate said rescue teams were trying to push their way further down the goods shaft. Rescue workers told Ukrainian television they believed other miners might still be alive at a depth of 1,000 metres, about where the explosion occurred.

"They say they have heard voices at two levels," Coal Industry Minister Viktor Poltavets told Fifth Channel television.

"For the moment we don't know what is going on at 1,000 metres. But it is our understanding that there are people up to that depth. So we have to get through faster."

The television said the two rescued miners were brought to the surface in a small metal cage, briefly examined and taken to hospital. Both appeared to be in good health.

Five staff on the surface suffered burns and other injuries after being struck by equipment tossed about in the explosion, which blocked the two main shafts. Veteran miners described it as one of the most powerful blasts experienced in the industry.

Gas explosions are a frequent occurrence in Ukraine's outdated mines, many of which are unprofitable and date from the 19th century.