Authorities in Turkey detained Sunday the director of the company managing a gold mine where a massive landslide in the country’s east left nine workers missing, local media said.

A huge landslide engulfed Tuesday the Anagold Madencilik company’s Copler mine in the town of Ilic in Turkey’s mountainous Erzincan province, trapping the workers under tons of rubble, and becoming a potential environmental disaster. The landslide involved a mound of soil extracted from the mine, Interior Minister Ali Yerlikaya previously said.

Cengiz Demirci, Turkey director and senior vice president of operations at the Denver-based SSR Mining Inc., Anagold’s parent company, was detained Sunday morning. Earlier this week, authorities also detained eight other Copler mine employees as part of the investigation into the disaster, six of whom were formally arrested.

Hundreds of search and rescue personnel are still looking for the workers who have been missing for six days so far.

Turkey’s Environment Ministry announced Saturday it was canceling Anagold’s environmental permit and license.

This handout photograph from the Turkish news agency DHA (Demiroren News Agency) shows a view of an area following a substantial landslide affecting a large area around the gold mine in the Ilic district of Erzincan, Feb. 13, 2024.

This handout photograph from the Turkish news agency DHA (Demiroren News Agency) shows a view of an area following a substantial landslide affecting a large area around the gold mine in the Ilic district of Erzincan, Feb. 13, 2024.

Experts warned the landslide could be an environmental hazard as the soil was laced with dangerous substances, including cyanide, used in gold extraction. They said it may affect the nearby Euphrates River which stretches across Turkey, Syria and Iraq. The ministry had closed down a stream leading to the river to prevent water pollution.

In 2020, the same mine was shut down following a cyanide leak into the Euphrates, roughly 3 kilometers (1.86 miles) away. It reopened two years later after the company was fined and a cleanup operation completed.

Shares at SSR Mining plummeted over 50% in the wake of Tuesday’s disaster.

Turkey has a poor mine safety record.

In 2022, an explosion at the Amasra coal mine on the Black Sea coast killed 41 workers. The country’s worst mining disaster took place in 2014 at a coal mine in the municipality of Soma, in western Turkey, where 301 people were killed.