Rescuers found one body on Friday, two days after a landslide in southern Norway swept away at least nine buildings, police said, with nine people still missing.

More than 30 homes have been destroyed, but officials say more could be lost as the edges of the crater left by the landslide are still breaking away.

The landslide began early on Wednesday, with residents calling emergency services and telling them that their houses were moving, police said.

Another 10 people were injured after Wednesday's landslide in the residential area in the Gjerdrum municipality, about 30 kilometres northeast of the capital, Oslo.

Emergency workers are continuing their search in what Bjoern Nuland, head of the health team at the site, said was still a rescue operation. A search-and-rescue team from neighbouring Sweden was assisting.

Some 1,000 people have so far been relocated from Gjerdrum, including 46 people from an area two kilometres away from the landslide, after cracks were observed in the ground.

Quick clay is a kind of clay found in Norway and Sweden that can collapse and behave as a fluid when it comes under stress.

Initially it was thought too dangerous to send rescuers on to the site, after flowing mud sent homes toppling into a giant chasm in the village of Ask.

Helicopters and drones spent two days searching the scene.

Friday's search was a race against time, as the rescuers only had a few hours of daylight in the Norwegian winter. Medics and geologists were reportedly part of the ground rescue team.

Although police have not given details of the missing, they are believed to include men, women and children.

Among them is a woman who was talking to her husband on the phone while walking the dog when the line went dead, according to Bergens Tidende newspaper.

Further reports say a couple and their small child are also missing, as well as a woman in her 50s and her adult son.