In Papua New Guinea, 64 people were killed in an intertribal massacre

The victims are believed to be tribal fighters who were ambushed by a rival group in the early hours of Sunday morning.

The incident happened near Wabag, which is about 600 kilometers northwest of the capital Port Moresby.

This harsh and lawless territory has been the scene of mass killings between rival Sikin, Ambulin, Kaekin and other tribes for years.

VIDEO: Tribal clashes kill 64 people: investigation launched in Papua New Guinea

Graphic police images from the scene show stripped and bloodied bodies lying by the road and piled on the back of a flatbed truck.

Some men had their limbs cut off and were left naked by the roadside with beer bottles or cans on their chests.

On Monday, police said gunfire was taking place in nearby valleys and bodies were still being found in bushes near the road.

“We believe there are still some bodies in the bushes,” Assistant Commissioner of Police Samson Kua said.

Clans living in the mountains have been fighting each other for centuries, but with the arrival of automatic weapons that are fueling the cycle of violence, the clashes are claiming more casualties.

Kua said the attackers used real weapons, including SLRs, AK-47s, M4s, AR15s and M16s, as well as pump-action shotguns and improvised firearms.