NAIROBI — Fifteen elephants were found dead in southern Kenya outside the boundaries of Amboseli National Park, and the Kenya Wildlife Service has launched an investigation into what it suspects was a mass poisoning.

Initial laboratory tests on samples from the carcasses detected traces of cyanide, leading KWS officials to suspect the animals were poisoned after ingesting pesticide-contaminated tomatoes from farms bordering the park, where elephants frequently forage.

Some wildlife experts have questioned whether pesticides were the definitive cause, suggesting other possibilities warrant consideration.

Elephants in the Amboseli region regularly venture outside protected areas in search of food and water, bringing them into contact with agricultural land. Farmers bordering national parks commonly apply chemicals to protect crops from wildlife.

Amboseli supports one of Africa's largest elephant populations, and the loss of 15 animals is a blow to conservation efforts in the ecosystem.

Further laboratory analyses are underway. KWS said it aims to identify the specific source of the contamination and prevent similar incidents, with findings expected to inform policy on land use and wildlife protection near protected areas.