The death toll from a coal mine explosion in northern Turkey has increased to at least 40 people.

Desperate relatives had waited all night in the cold outside the state-owned TTK Amasra Muessese Mudurlugu mine in the town of Amasra, in the Black Sea coastal province of Bartin, hoping for news.

There were 110 miners working in the shaft when the explosion occurred on Friday evening.

Interior minister Suleyman Soylu said on Saturday that 40 miners were confirmed dead. Eleven were injured and in hospital, while 58 others managed to get out of the mine on their own or were rescued unharmed.

The status of one remaining miner is unclear.

Energy minister Fatih Donmez said rescue efforts are almost complete. Earlier he had said a fire was still burning in the mine’s gallery where more than a dozen miners had been trapped.

Work to isolate and cool the fire continues, he said.

Preliminary assessments indicate the explosion was caused by firedamp, which is a reference to flammable gases found in coal mines, Mr Donmez said overnight.

A miner who works the day shift said he saw the news and hurried to the site to help with the rescue.

Celal Kara, 40, said: “We saw a frightful scene, it cannot be described, it’s very sad.

“They’re all my friends… they all had dreams.”

Turkey’s president Recep Tayyip Erdogan is expected to visit Amasra on Saturday.

He said three prosecutors had been assigned to investigate the incident.

In Turkey’s worst mine disaster, 301 people died in 2014 in a fire inside a coal mine in the town of Soma, in western Turkey.