A blast at a coal mine in northern Turkey has left 22 workers dead, with rescuers working through the night trying to bring dozens of others trapped to the surface.

The explosion occurred at 6:45pm local time at the state-owned TTK Amasra Muessese Mudurlugu mine in the town of Amasra in the Black Sea province of Barin, Turkish authorities said.

Interior Minister Suleyman Soylu said at least 28 miners were rescued with injuries from the mine, where 110 people were working at the time of the explosion.

“We are faced with a picture that we truly regret, that we regret to have to share (with the public),” Mr Soylu said. 

The cause of the blast was unknown, Turkey's Disaster Management Authority (AFAD) said, retracting an earlier statement that it was caused by a transformer.

Energy Minister Fatih Donmez said a preliminary assessment indicated the explosion was likely caused by firedamp — a reference to flammable gases found in coal mines.

There were conflicting reports on the number of people still trapped.

Provincial governor Nurtac Arslan said 49 people were waiting to be brought to the surface, while mining trade union Maden-Is reported 35 were still trapped.

The explosion occurred 300 metres below the entrance of the mine, Mr Arslan's office said.

Several rescue teams were dispatched to the area, including from neighbouring provinces, AFAD said.

Footage on Turkish television showed what it said were the families of the miners watching from the sidelines as health and rescue workers huddled around the entrance into the mine.

Some miners were taken out and carried off to ambulances on stretchers, footage showed.

President Recep Tayyip Erdogan announced he was cancelling a planned visit to the south-eastern city of Diyarbakir and would travel to Amasra instead to coordinate the rescue operation. 

In Turkey’s worst mine disaster, a total of 301 people died in 2014 after an explosion caused a coal mine to collapse in the town of Soma, in western Turkey.

ABC/wires