PORT MORESBY: The discovery of dozens of bloodied bodies in Papua New Guinea's highlands has thrust the region's long-running and increasingly deadly tribal violence into international headlines.
Here is what we know so far:
What happened?
At around 4am on Sunday, a clash between rival tribal fighters near the highland village of Wapenamanda left between 49 and 64 dead, according to officials, with the toll looking set to increase as bodies continue to be found.
Reliable eyewitnesses are difficult to come by, and accounts from even the most senior government officials often don't add up.
But a picture is starting to emerge of an ambush by one tribal group against a rival one that was preparing an attack.
Police sources say the ambushed men were hacked down with machetes and axes or shot with high-powered semi-automatic weapons.
Bodies were found along the road and in nearby bushland, indicating that some of the victims may have been killed as they tried to flee.
The incident is believed to have continued for hours before authorities were able to reach the area and collect the bodies. There are unconfirmed reports that officers also came under fire.
Why did it happen?
There are vastly difficult accounts of what sparked this latest attack, but it is clearly tied to long-running tribal feuds that date back decades or more.
In the last year alone, there have been reports of tribesmen using vehicles to drag the corpses of rivals along roads, the killing of one man at a funeral and the deaths of five others in retaliation.
For decades, villages in the area have been raided, homes, schools and churches burned, and women raped. There have also been efforts to destroy water tanks and dig up food crops of rival clans.
Anthropologists and other researchers have pointed to the fast-growing population in the highlands as fueling a scarcity of resources that has brought tribes into conflict.
But drunken arguments, theft, adultery, accidents, political rivalries and even allegations of witchcraft—which often see suspected witches brutally tortured and killed—have been known to spark unrest.
Anger has been fuelled in recent years by extremely graphic and provocative posts shared via phone messages or on social media, while messages of incitement are a growing problem.
Policing in the area is patchy at best, and minor crimes are rarely dealt with by the under-armed, under-staffed and under-trained force, allowing disproportionate "jungle justice" to take hold.
Who is fighting?
Much of the recent violence, including Sunday's attack, has involved Ambulin-allied tribes and their Sikin rivals.
But the violence across the central Enga province has drawn in more than a dozen rival tribes, including the Sikin, Kaekin, Senek, Ambulin, Itokane, Epok and Sau, and spurred ever-changing tribal blood alliances.
Some local officials suggested those who died on Sunday were mostly mercenaries hired from across the highlands to help prosecute a long-running grudge.
Others said most of the dead were from the Sikin tribe, who were killed by the Ambulin or their allies.
How widespread is the problem?
Australian researcher Miranda Forsyth has tried to quantify the size and scope of the violence in the highlands.
Forsyth and her team found local media reports of 158 tribal fights and a total of 1,896 people killed between 2018 and 2022.
That number is likely vastly underreported, and deadly attacks are known to have occurred at least as early as 1996.
Elderly tribesmen in the area readily recall fights over rape, theft and tribal boundaries that were solved half a century ago with bows, arrows, axes and spears.
Today, those problems are just as likely to be solved by American M16s, AR-15s or Belgian FN rifles, pushing the death tolls higher.