Sixty-four bloodied bodies have been found in Papua New Guinea's highlands, police said Monday, as officers reported ongoing gun battles between rival tribes.
Assistant Commissioner of Police Samson Kua said the bodies had been found after what is believed to be an ambush in the early hours of Sunday.
"We believe there are still some bodies... out there in the bush," he told AFP.
The incident occurred near the town of Wabag, 600 kilometres (370 miles) northwest of the capital Port Moresby.
Police received graphic videos and photos purporting to be from the scene.
They showed stripped and bloodied bodies lying by the side of the road and piled up on the back of a flatbed truck.
The incident is thought to be linked to a conflict between Sikin, Ambulin and Kaekin tribesmen.
Highland clans have fought each other in Papua New Guinea for centuries, but an influx of automatic weapons has made clashes more deadly and escalated the cycle of violence.
- Mass killings -
Kua said the gunmen had used a veritable armoury, including SLR, AK-47, M4, AR15 and M16 rifles, as well as pump-action shotguns and home-made firearms.
It is believed that fighting is ongoing in a remote rural area nearby.
Papua New Guinea's highlands have been the scene of persistent tribal violence, with several mass killings in recent years.
Papua New Guinea's government has tried suppression, mediation, amnesties and a range of other strategies to control the violence, with little success.
The military had deployed about 100 troops to the area, but their impact has been limited and the security services remain outnumbered and outgunned.
The killings often take place in remote communities, with clansmen launching raids or ambushes in revenge for previous attacks.
Civilians, including pregnant women and children, have been targeted in the past.
The murders are often extremely violent, with victims hacked with machetes, burned, mutilated or tortured.
Police privately complain that they do not have the resources to do the job, with officers so badly paid that some of the weapons that end up in the hands of tribesmen have come from the police force.
Opponents of Prime Minister James Marape's government on Monday called for more police to be deployed and for the force's commissioner to resign.
Papua New Guinea's population has more than doubled since 1980, placing increasing strain on land and resources and deepening tribal rivalries.