More than 2,500 dead seals have washed up on the coast of the Caspian Sea in Russia's Dagestan region, the natural resources ministry said on Monday.
"Along the entire coast of the Caspian Sea on the territory of the republic, specialists of environmental structures are continuing measures to count the number of dead seals," Dagestan's natural resources ministry said.
The cause of the deaths was not immediately clear but tests are being carried out, a spokeswoman said.