(CNN)— Authorities in Peru are investigating the death of over 538 pelicans, along with
other birds, on the northern coast of the country, the Peruvian ministry of production said Sunday.
The new environmental investigation comes on the heels of an incident earlier in April when 877 dolphins washed up dead on the same stretch of coast.
It was not immediately clear if the deaths were connected.
The birds appear to have died on the beach, and more tests are needed to determine the cause of death, the ministry of production said.
The Peruvian Sea Institute surveyed about 43 miles (70km) of beach coastline on Sunday and estimated that 592 birds were dead along the shore.
State-run TV Peru estimated that up to 1,200 birds had been found dead on the 100 miles (160km) of northern shoreline extending from Punta Negra in Piura to San José in the state of Lambayeque.
The deaths began less than two weeks ago, local fishermen say.