An explosion at an underground coal mine in Turkey has injured 11 miners and at least 25 others are missing, according to officials and local news reports.

The blast occurred at the state-run Karadon coal mine near the Black Sea port of Zonguldak in the country’s north.

Efforts are underway to reach the workers at the coal mine while the injured are treated at a nearby hospital.

The cause of the blast is not yet known.

The blast comes three months after an explosion at the Odakoy mine which killed 13 people near the town of Dursunbey in north-western Balikesir province.

The country’s worst mining disaster happened in 1992, when 270 workers were killed in another mine near Zonguldak.