Peru is investigating the deaths of some 500 sea lions found on a beach on its northern coastline.
The local governor has accused fishermen of poisoning the mammals, which usually come close to the shore looking for food.
But Peruvian environmental police are looking into other possible causes for the deaths, including disease and the accidental ingestion of plastic.
The rotting corpses were found on Anconcillo beach in the Ancash region.
Agents said the bodies were of young as well as old animals, the official Andina news agency reported.
They were considered a health hazard and quickly removed from the beach, which lies some 400km (250 miles) north of the capital, Lima.
Earlier this month, a similar incident happened further north, in the Piura region, where the bodies of nearly 200 sea lions, dolphins, turtles and pelicans washed ashore.
Officials are still investigating the causes of those deaths.
Hundreds of dolphins were washed up in north Peru two years ago
In 2012, hundreds of dolphins were found dead along a stretch of Peruvian coastline.
Environmental group Orca blamed the deaths on the noise and pressure waves caused by explosions it linked to oil exploration in the area.
But a government report by the Maritime Institute (Imarpe) ruled out oil exploration, or infection by a virus or bacteria, as triggers for the deaths of the dolphins.
The report said natural causes were to blame.