MOSCOW (AP) -- Rescue teams on Sunday found the bodies of nine construction workers who were trapped inside a burning potash mine in Russia's Ural Mountains.
A fire erupted Saturday at the mine operated by fertilizer company Uralkali in the Perm region. , Uralkali said two teams of workers were doing maintenance work in the mine and operations had been suspended while they labored.
Officials said 17 construction workers were inside the mine in Solikamsk, which is located 1,200 kilometers (740 miles) east of Moscow, when the fire broke out and eight of them were quickly evacuated. The blaze cut off access to nine other workers who were in a different section.
Russian news agencies quoted the rescue headquarters as saying Sunday that all nine bodies had been located and were being recovered. Two bodies were taken out by late Sunday afternoon. Firefighters were still putting out the blaze.
The Perm region declared Monday a day of mourning for the workers.
Russian President Vladimir Putin urged regional authorities and investigators to conduct a thorough probe into what happened inside the mine.
Authorities were treating the incident as a result of lax safety procedures. The Investigative Committee said Sunday it launched a criminal probe of possible safety violations and had detained four employees of the subcontractor which was in charge of the maintenance work.
Poor safety standards are often to blame for recurring accidents in Russian mines. The last major Russian mining accident took place in August 2017, when 17 people died after a diamond mine in Siberia flooded.