The International Organization for Migration has increased its estimate of the death toll from a massive landslide in Papua New Guinea (PNG) to more than 670.

Serhan Aktoprak, the chief of the United Nations agency's mission in the South Pacific island nation, said on Sunday the revised death toll was based on calculations by Yambali village and Enga provincial officials that more than 150 homes had been buried by Friday's landslide.

The previous estimate had been 60 homes.

"They are estimating that more than 670 people [are] under the soil at the moment," Aktoprak said.

"The situation is terrible with the land still sliding. The water is running and this is creating a massive risk for eveyrone involved," added Aktoprak, who is based in capital, Port Moresby.

Local officials had initially put the death toll on Friday at 100 or more. Only five bodies and a leg of a sixth victim had been recovered by Sunday, while seven people, including a child, had received medical treatment.

Authorities are trying to establish evacuation centres on safer ground on either side of the massive swath of debris.

Meanwhile, emergency responders were moving survivors of the massive landslide to safer ground as tonnes of unstable earth and tribal warfare, which is rife in the country's highlands, threatened the rescue effort.

Damage to infrastructure also made it more difficult for rescue and relief efforts to reach the area, according to Justine McMahon, a CARE Australia humanitarian group representative in PNG.

"The ground is quite unstable, making it difficult for rescuers to get in. The main road has also been cut off by about 200 metres [656 feet], hampering relief," she told Al Jazeera.

Car-sized boulders

Heavy earth-moving equipment are yet to arrive at the mountainous location 600km (370 miles) northwest of Port Moresby.

At some points, the landslide - a mix of car-sized boulders, uprooted trees and churned-up earth - was thought to be 8 metres (26 feet) deep.

Aid agencies said the catastrophe had effectively wiped out the village's livestock, food gardens and sources of clean water.

A Papua New Guinea government official has told the United Nations that more than 2,000 people are believed to have been buried alive by last Friday's landslide and has formally asked for international help.

The government figure is roughly triple the U.N. estimate of 670 killed by the landslide in the South Pacific island nation's mountainous interior. The remains of only five people had been recovered by Monday, local authorities reported. It was not immediately clear why the tally of six reported on Sunday had been revised down.

In a letter to the United Nations resident coordinator dated Sunday and seen by The Associated Press, the acting director of the country's National Disaster Center, Luseta Laso Mana, said the landslide "buried more than 2,000 people alive" and caused "major destruction" in Yambali village in Enga province.

Cyclone toll in Bangladesh and India rises to 65

A powerful cyclone that smashed into low-lying Bangladesh and India killed at least 65 people, including in torrential rain storms in its wake, state government officials and media said Wednesday.

Cyclone Remal, which made landfall on Sunday evening with fierce gales and crashing waves, moved slowly inland causing floods and triggering landslides.