According to the interior minister of Turkey, 40 persons are now believed to have perished as a result of an explosion in a coal mine in the country's north.
58 individuals had reportedly been evacuated from the mine, according to Suleyman Soylu, while more than a dozen were still inside.
Nearly half of the 110 persons who were inside the mine at the time of the incident on Friday were more than 300 meters below the surface.
To try to reach additional survivors, rescue teams dug through rocks all night long.
At the mine near Amasra, on the Black Sea coast, rescuers can be seen arriving with blackened and sleep-deprived workers.
There were also witnesses at the mine who were concerned about the well-being of their loved ones who were gone.
"Fifty-eight of our miners were able to come out unharmed. We estimate that 15 of our miners are trapped below and we are trying to rescue them," Mr Soylu told reporters at the scene.
The explosion is thought to have happened 300 meters or more below the surface. According to Mr Soylu, 49 employees have been employed in the "risky" area between 300 and 350 meters (985 and 1,150 feet) below ground.
The local prosecutor's office has started an inquiry even though the cause of the explosion is yet unknown.
The explosion may have been caused by firedamp, which is methane generating an explosive combination in coal mines, according to Turkey's energy minister.
"We are facing a truly regretful situation", he said.
He said that there were no active flames and that ventilation was operating as it should have been and that there were partial collapses inside the mine.