More than 670 people have died in Papua New Guinea’s landslide, the UN migration agency estimated on Sunday as rescue efforts continued.

Media in the South Pacific nation north of Australia had previously estimated Friday’s landslide had buried more than 300 people. The International Organization for Migration (IOM) said earlier on Sunday that only five bodies had been retrieved from the rubble.

The agency based its estimate of the death toll on information provided by officials at Yambali Village in the Enga province, who have said that more than 150 houses were buried in Friday’s landslide, Serhan Aktoprak, the chief of the agency’s mission in Papua New Guinea said in a statement.

More than six villages have been impacted by the landslide in the province’s Mulitaka region, about 600 km (370 miles) from the capital Port Moresby, said Australia’s Department of Foreign Affairs and Trade.

“Land is still sliding, rocks are falling, ground soil is cracking due to constant increased pressure, and ground water running in this area is posing an extreme risk for everyone,” Mr Aktoprak said.

More than 250 houses nearby have been abandoned by the inhabitants, who had taken temporary shelter with their relatives and friends, and some 1,250 people have been displaced, the agency said.

“People are using digging sticks, spades, large agricultural forks to remove the bodies buried under the soil,” Mr Aktoprak said.

The IOM said that more than 100 houses, an elementary school, small businesses and stalls, a guesthouse, and a petrol station were buried.

Social media footage posted by villager Ninga Role showed people clambering over rocks, uprooted trees and mounds of dirt searching for survivors. Women could be heard weeping in the background.

The UN’s Papua New Guinea office said three bodies were retrieved from an area where 50 to 60 homes had been destroyed, while six people, including a child, were pulled from rubble alive.

It said many of those buried were yet to be located as search and rescue efforts continued in the mountainous area of the country, which shares the island of New Guinea with Indonesia.

Aid group Care Australia said late on Saturday that nearly 4,000 people lived in the impact zone but the number affected was probably higher as the area is “a place of refuge for those displaced by conflicts” in nearby areas.

At least 26 men were killed in Enga Province in February in an ambush amid tribal violence that prompted prime minister James Marape to give arrest powers to the country’s military.

The landslide left debris up to 8 metres (25 feet) deep across 200 square km (80 square miles), cutting off road access and making relief efforts difficult, Care said. Helicopters were the only way to reach the area, the Australian Broadcasting Corp reported.

Aid groups have said more homes could be at risk if the landslide continues down the mountain, as the terrain remains unstable.

Mr Marape has said disaster officials, the Defence Force and the Department of Works and Highways were assisting with relief and recovery efforts.