PORT MORESBY, Papua New Guinea — Rescuers digging through mud and rocks at a Papua New Guinea landslide that killed an estimated 670 people say they are being obstructed by falling debris, dangerous terrain and tribal fighting along a key supply route.

A once-bustling remote hillside village in Enga province was almost wiped out when a chunk of Mount Mungalo collapsed in the early hours of Friday morning, burying scores of homes and the people sleeping inside them.

Locals have been using shovels and pieces of wood to find bodies under the landslide — a mix of car-sized boulders, uprooted trees and churned-up earth that is thought to be up to eight meters (26 feet) deep.

"The landmass is still sliding, rocks are falling from the mountain," UN migration agency official Serhan Aktoprak told Agence France-Presse.

Streams of water were flowing between the soil and debris while cracks were appearing in land adjacent to the landslip, Aktoprak said.

"This might trigger a further sliding," the UN official warned, posing a "serious risk" both to rescuers and people living in the area.