Russian emergency workers on Monday ended a rescue operation at a mine in the country’s Far East where 13 workers are presumed dead after an accident two weeks ago, state media reported.

A landslide on 18 March at the Pioneer gold mine in Russia’s Amur region near the Chinese border pinned the miners more than 120 meters underground.

Initial search operations showed caverns where they could have been sheltering were flooded, raising fears the 13 had been killed in the landslide.

“On 1 April, a decision was made to terminate the rescue operation at the Pioneer mine,” operator Pokrovsky Mine said in a statement cited by the Interfax news agency.

“The results of drilling showed the areas where the miners could be are filled with rock mass and water. The lives of rescuers and mine workers involved in the operation are at risk of death,” due to the possibility of another collapse, it added.

The gold mine is one of the largest in the world and one of the most productive in Russia.

Officials in Amur have opened an investigation for a suspected breach of safety rules. The managing director was arrested last week, the regional branch of Russia’s Investigative Committee, which probes major crimes, said.

Accidents at mines are relatively common in Russia, where lax safety standards and weak enforcement have been blamed for multiple tragedies. In 2021, an accident at a coal mine in Siberia claimed the lives of 40 miners.

Kremlin spokesperson Dmitry Peskov said Monday the termination of the rescue mission was “not good news.”

“All the measures that could have been taken in connection with the situation that arose were taken. But the situation is what it is,” he told reporters.

The regional governor said emergency workers had tried to save the miners “at great risk to their lives” and that the families of the miners would be given financial support.