Nine workers are believed to be trapped underground after a landslide hit a gold mine in eastern Turkey on Tuesday, officials said.

The landslide at the Copler mine happened at 2.30pm local time near the town of Ilic in Turkey’s mountainous Erzincan province.

Interior minister Ali Yerlikaya said nine workers have not been heard from since the landslide struck and that 400 search and rescue personnel are at the site.

Emergency agency Afad said staff from surrounding provinces have been brought in.

“There are people buried underground, the number is not clear. Our search and rescue efforts have started,” regional governor Hamza Aydogdu said.

Meanwhile, Erzincan Mayor Bekir Aksun told broadcaster Haberturk that between 10 and 12 workers are missing.

Anagold Mining has operated the Copler mine since 2009, and minister Yerlikaya said 667 staff are employed at the site.

In a statement, the company said its “most important priority in this difficult process is the health and safety of our employees and contractors”.

“This is a painful situation,” it added. “Immediately after the incident, we immediately contacted our employees in the region, put our emergency plan into action and informed the relevant public institutions and organisations.”

Justice Minister Yilmaz Tunc said an investigation into the disaster has been launched, adding: “I wish our citizens from Erzincan recover soon and hope that our miner brothers who are trapped under the rubble will be rescued safely.”

Geologist Suleyman Pampal told Haberturk the soil that formed the landslide had been processed for gold and may contain dangerous substances such as cyanide which are used in the process.

He also warned of an environmental threat to the nearby Euphrates river.

“Mixing with the Euphrates means the end of all life. It must be prevented urgently from reaching the Euphrates,” he said.

The Environment Ministry said in a statement that a stream leading to the Euphrates was closed to prevent water pollution.

Erzincan govenor Hamza Aydogdu said no cyanide had gotten into the waterway.

“There is no leakage at the moment,” he said. “If there were, we would explain it to you.

“There is no leakage into the Euphrates River. There was a landslide, so there is no problem other than this landslide.”

The mine was closed down in 2020 following a cyanide leak into the river, which stretches through Turkey, Syria and Iraq.

It reopened two years later after the company was fined and a clean-up operation was completed.

The Turkish government said social media content about the disaster that “has not been confirmed through official channels and whose accuracy is not assured” had been blocked.

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 Soma, western Turkey, which saw 301 people killed.

In the wake of the incidents, engineers warned that safety risks were frequently ignored and inspections not adequately carried out.

“The disaster that took place in Erzincan Ilic Copler gold mine is a disaster that (was) coming,” the Union of Chambers of Turkish Engineers and Architects said in a statement issued on social media.

The union added that it had filed two lawsuits against the mine’s operation, adding: “We said that Ilic Copler gold mine should be closed and rehabilitation works should be started”.