Around 1,700 seals have been found dead on the Caspian Sea coast in southern Russia, officials have said.
Authorities in the Russian province of Dagestan said it remained unclear what had caused the animals’ deaths, but that it was likely they had died of natural causes.
Regional officials initially said on Saturday that 700 dead seals had been found on the coast, but Zaur Gapizov, head of the Caspian Environmental Protection Center, said on Sunday – according to the state RIA Novosti news agency – that following a broader inspection of the coast the number of dead animals was 1,700.
Mr Gapizov said the seals were likely to have died a couple of weeks ago. He added that there was no sign they had been killed by poachers.
Federal Fisheries Agency experts, together with prosecutors, inspected the coastline and collected data for laboratory research, which did not immediately spot any pollutants.
Several previous incidents of mass deaths of seals have been attributed to natural causes.
The data about the number of seals in the Caspian varies widely.
The fisheries agency has said the overall number of Caspian seals is between 270,000 and 300,000, while Mr Gapizov’s center puts the number at 70,000.