Turkish mine explosion kills 22 and leaves dozens trapped

At least 22 people have died and dozens remain trapped underground after an explosion in a coal mine in northern Turkey's Bartin province.

At least 110 people were working in the mine at the time of the blast, dozens of them at a depth of more than 300 metres below the surface.

Rescuers were digging through hard rock to try to try to reach survivors, Turkey's interior minister said.

Earlier the provincial governor said eight miners had managed to escape.

Video footage shows miners emerging blackened and bleary-eyed accompanied by rescuers at the facility in Amasra on the Black Sea coast.

Hundreds of emergency service workers and the family and friends of the missing could also be seen at the mine as rescuers worked through the night.

The cause of the blast isn't yet known, but the local prosecutors office has begun an investigation.

Turkey's energy minister said there were initial indications that the blast was caused by firedamp, which is methane forming an explosive mixture in coal mines.

"We are facing a truly regretful situation", he said to reporters.

Turkish President Recep Tayyip Erdogan is expected to visit the site on Saturday.

Amasra's mayor Recai Cakir said many of those who survived had suffered "serious injuries".

One worker who managed to escape on his own said "There was dust and smoke and we don't know exactly what happened."