Hundreds of Turkish rescuers on Tuesday searched through a cyanide-laced field for nine gold mine workers who were swallowed by a massive landslide that rolled over their open pit.
Images from the scene showed the landslide sweeping across a valley and crashing into a road where some of the workers were travelling by vehicle.
Interior Minister Ali Yerlikaya said there was no news of nine out of 667 employees at the mine, which is in the remote Ilic district of the eastern Erzincan province.
"We installed our (rescue) vehicles, our generators, and our night lighting equipment," Yerlikaya told state-run TRT television. "We have only one wish: to be able to give good news to the families of these brothers."
Experts and local officials said the search was complicated by the presence in the ground of cyanide -- a highly toxic chemical compound used to extract gold from ore.
"Cyanide soil collapsed" at the site, Independent Mining Labour Union representative Basaran Aksu told Turkish media.
Aksu said specialist equipment would be needed in the search.
"The work may take a very long time because of the cyanide field," which is reported to be one of Turkey's largest.
The province lies on the northern bank of the Karasu River -- a major tributary of the Euphrates, which runs from Turkey to Syria and Iraq.
The environment ministry said it had sealed off a stream that runs from the open pit to prevent contamination of the Euphrates.
Environmental activists and local officials tried to shut down the open pit mine after a 2022 cyanide leak.
The plant closed for a few months but then re-opened after its operator paid a fine, prompting an outcry from Turkey's opposition parties.
Cemalettin Kucuk, an engineer who co-authored a report into the mine's safety when its operator sought permission to expand its capacity, said the soil was filled with "stone fragments containing cyanide".
"We are talking about a mountain weighing millions of tonnes," Kucuk told Turkish media. "We have warned about this many times."
Mehmet Torun, the former president of the Chamber of Mining Engineers, explained that the huge pile of soil sliding towards the Euphrates River consists of materials washed with cyanide and sulfuric acid.
"For years, that mountain was being blown up, gold extracted from it.... and the waste was piled aside like a mountain of garbage. Now this huge mass, bathed in cyanide, flows towards the Euphrates River," he warned.
Anagold, a private company that runs the Ilic mine, said it was working to minimise the effects of this "painful" incident.
"We will mobilise all our means in order to urgently shed light on this incident," Anagold said in a statement.
The justice ministry on Tuesday assigned four public prosecutors to investigate the mine's operations.
Turkey is prone to deadly landslides and has suffered a string of mining accidents in recent decades.
A methane blast at a coal mine in northwest Turkey killed 42 people in October 2022.