An official inspects a dead Sumatran elephant allegedly poisoned by poachers for its tusks, in Bireum Bayeun, Aceh province, Indonesia, Friday, June 1, 2012. Three Sumatran elephants were found dead from poisoning Friday. Indonesia's endangered elephants on Sumatra island are threatened by habitat loss and poaching. Less than 3,000 Sumatran elephants are believed to remain in the wild. (AP Photo/Iskandar)

(AP) — An environmentalist says three endangered Sumatran elephants have been poisoned and found dead within a palm oil plantation in western Indonesia.

Rono Wiranata from the FAKTA nongovernment group said workers at the state-run plantation were believed to have placed the poison on palm fruits. The dead 3- and 5-year-old were found Thursday in two separate locations in East Aceh district.

Wiranata on Friday cited workers in saying more elephants may die from the poison.

Five of the endangered Sumatran elephants have been found poisoned in Aceh province since April.

Fewer than 3,000 Sumatran elephants are left in the wild. Environmentalists say they could be extinct within three decades unless they are protected.