MELBOURNE, Australia >> Violence among illegal miners in Papua New Guinea has left between 20 and 50 people dead, a United Nations official said Monday.

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 2,000 people, according to the South Pacific island nation’s government.

The U.N.’s humanitarian adviser for Papua New Guinea, 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. “The fighting is continuing.”

“Today some security forces have started moving in ... so it remains to be seen what effect this will have,” Bagossy said, referring to the army and police.

Bagossy did not have information on the numbers wounded.

Papua New Guinea police did not respond to a request Monday for tallies of dead and wounded in the valley.

National Police Commissioner David Manning said an emergency had been declared Saturday after the violence escalated, with police mobilizing to protect residents and infrastructure.

“The deteriorating situation has been caused by illegal miners and illegal settlers who are victimizing traditional landowners and using violence to terrorize local communities,” Manning said in a statement.

The nearby New Porgera gold mine has halted most of its operations because of the violence until at least Thursday.

“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 Sunday.

“I am incredibly saddened by these devastating events and sincerely hope that the government will soon restore peace to the valley,” McTiernan added.

Enga Governor Peter Ipatas described the violence in the valley as unprecedented.

“This situation is dire. We have witnessed innocent lives being claimed and properties destroyed within days. The current situation can’t continue,” Ipatas said in a statement.

A disaster management team led by the national government and the U.N. Development Program will meet in the national capital, Port Moresby, on Tuesday to coordinate a humanitarian response in a dangerous and remote environment.

Tribal warfare is a growing security problem across Papua New Guinea and is rife in Enga, where recovery has been slow since the May 24 landslide.

The United Nations conservatively estimated 670 villagers had died, while the Papua New Guinea government said more than 2,000 people had been buried.