Turkish police have reportedly arrested 25 people over a mine explosion that killed 41 people earlier this month.
The manager of the state-owned in Amasra and several other executives were among those arrested, according to the Anadolu news agency.
A firedamp explosion on 14 October destroyed the mine near the small Black Sea town in northern Turkey, killing 41 miners and injuring 11 others.
Turkish President Recep Tayyip Erdoğan had promised a full investigation into the disaster and said "no one would be spared" if found responsible.
Workers had reportedly complained about a "smell of gas" in the mine for several days before the deadly blast.
Turkey's opposition has accused Erdoğan's government of negligence and failing to prevent the disaster.
More than 300 people were killed in an explosion and fire in a coal mine in the Turkish town of Soma in 2014.