Between 20 and 50 people have been killed in violence among illegal miners in Papua New Guinea, a UN official says.
The fighting started days ago and is continuing in the Porgera Valley, near the site of a landslide in May estimated to have killed more than 2000 people, according to the Pacific island nation's government.
The UN's humanitarian adviser for PNG, Mate Bagossy, said the death toll of at least 20 as of Sunday was based on information from community members and local authorities in Enga province in the nation's mountainous inland.
"We have confirmed that at least 20 people have been killed, but as per the last news that I have, it's likely up to 50 people," Bagossy told The Associated Press.Â
"The fighting is continuing. Today some security forces have started moving in ... so it remains to be seen what effect this will have," Bagossy added, referring to the army and police.
National Police Commissioner David Manning said an emergency had been declared on Saturday after the violence escalated, with police mobilising to protect residents and infrastructure.
"The deteriorating situation has been caused by illegal miners and illegal settlers who are victimising traditional landowners and using violence to terrorise local communities," Manning said in a statement.
The nearby New Porgera gold mine has halted most of its operations until at least Thursday because of the violence.
"Over the past 24 hours a significant escalation in tribal fighting has impacted many of our local employees. Homes have been destroyed, family and friends injured or killed, and people have been unable to sleep while living in fear," New Porgera general manager James McTiernan said in a statement on Sunday.
"I am incredibly saddened by these devastating events and sincerely hope that the government will soon restore peace to the valley."
Tribal warfare is a growing security problem across PNG and is rife in Enga where a massive landslide on May 24 is estimated to have buried hundreds of villagers.
The UN conservatively estimated 670 villagers had died, while the PNG government said more than 2000 people had been buried.
An unknown number of refugees from tribal violence in neighbouring areas are thought to be among the casualties, adding to the complications in calculating a credible death toll.
Continued fighting on the road from the disaster area to the provincial capital Wabag delayed the emergency response. Relief workers required army escorts to keep them safe.
Pope Francis called for an end to tribal violence during a recent visit to the majority-Christian nation of an estimated 12 million people.
Recovery from the landslide has been slow.
Four months after the disaster, the main highway through the province remains buried under the collapsed mountainside.
No heavy earthmoving equipment has been used on the huge expanse of boulders, splintered trees and mud for fear of triggering a second landslide, the UN's International Organisation for Migration said.
A 4.7km bypass road that would be safe from landslides was half-finished, the UN organisation said.
Around 5000 people remain in the pathway of a potential second landslide in what authorities describe as a high-risk zone downhill from the disaster.
The provincial government is attempting to buy land outside the danger area to resettle those villagers, but complex negotiations have yet to be finalised, the organisation said.