KATHMANDU, Nepal (AP) — An old explosive device left during Nepal’s decadelong communist insurgency has killed four children in a mountain village, official said Friday.

The children picked up the device from the jungle and were playing with it when it exploded Thursday night and killed them, said government administrator Navaraj Sharma.

Government investigators had reached the village in Rolpa district on Friday but were unable to retrieve the bodies because of safety concerns. Villagers were also angry and protesting the deaths.

Nepal’s communist insurgency began in 1996 and ended a decade later after the rebels entered a United Nations-monitored peace process. Some 17,000 people are believed to have been killed in the fighting.

Rolpa district, located 400 kilometers (250 miles) west of Kathmandu, was the rebel stronghold during the fighting.