Emergency crews in Papua New Guinea are moving survivors of a massive landslide – feared to have buried scores of people – to safer ground as unstable earth and tribal warfare, which is rife in the area, threatens the rescue effort.

Rescuers say they have given up hope of finding survivors under earth and rubble up to 26ft deep after a landslide wiped out part of Yambali village in Enga province a few hours before dawn on Friday.

Local authorities on the South Pacific island initially estimated the death toll could be around 100, but others fear many more have died.

Serhan Aktoprak, the chief of the International Organisation for Migration’s mission in Papua New Guinea, said: “Hopes to take the people out alive from the rubble have diminished now.

“People are coming to terms with this so there is a serious level of grieving and mourning.”

Only five bodies had been dug out of the debris by hand by late Saturday, with heavy earth-moving equipment yet to arrive at the mountainous location 370 miles north-west of the capital Port Moresby.

Estimates of the number of homes destroyed were revised up from 60 on Saturday to more than 100 on Sunday.

Government authorities are establishing evacuation centres on safer ground on either side of the massive swathe of debris that covers an area the size of three to four football fields and has cut the main road through the province.

Mr Aktoprak said working in the debris is very dangerous and the land is still sliding.

As well as the blocked road, convoys that have transported food, water and other essential supplies since Saturday to the devastated village have faced risks related to tribal fighting in Tambitanis, which is about halfway along the route from the nearest large town. Papua New Guinea soldiers are providing security for the convoys.

Eight locals were killed in a clash between two rival clans on Saturday in a longstanding dispute unrelated to the landslide. Around 30 homes and five retail businesses were burned down in the fighting, local officials said.

Tribal warfare has cast doubt on the official estimate that almost 4,000 people were living in the village when a side of Mount Mungalo fell away.

Justine McMahon, country director of the humanitarian agency Care International, said that figure was based on an out-of-date census and did not take into account the recent movements of refugees fleeing tribal violence in the region.

“The authorities do anticipate that the number of casualties will rise,” Ms McMahon said.

“Because of tribal fights, other displaced people had moved into the area, so they do expect that the population is much bigger than the official figures indicate.”

She said moving survivors to “more stable ground” is an immediate priority, along with providing them with food, water and shelter.

The numbers of injured and missing were still being assessed on Sunday. Seven people including a child had received medical treatment by Saturday, but officials had no details on their conditions.

Medical facilities were buried along with more than 100 houses, several small businesses, a guest house, a school and a petrol station, officials said.

Ms McMahon said there are other health facilities in the region, the provincial government is sending health workers and the World Health Organisation is mobilising staff.

“There will be some support, but it’s such a spread out area that I think it will be quite a challenging situation,” she said.

“The scale of this disaster is quite immense.”