Norwegian officials insisted that there was "still hope" in finding survivors in air pockets five days after a landslide killed at least seven people as it carried away homes in a village north of the capital.

Three people are still missing.

Police spokesman Roger Pettersen said search efforts in the landslide-hit village of Ask, 16 miles northeast of Oslo, are still considered "a rescue operation".

But only bodies have been found in the last few days.

The region's below-freezing temperatures are "working against us, but we have been very clear in our advice to the (rescuers) that as long as there are cavities where the missing may have stayed, it is possible to survive", said Dr Halvard Stave, who taking part in the rescue operation.

Search teams patrolled with dogs as helicopters and drones with heat-detecting cameras flew amid harsh winter conditions over the ravaged hillside in Ask, a village of 5,000 that was hit by the worst landslide in modern Norwegian history.

At least 1,000 people were evacuated.

The landslide early on Wednesday cut across a road through Ask, leaving a deep, crater-like ravine.

Photos and videos showed buildings hanging on the edge of the ravine, which grew to be 2,300 feet long and 1,000 feet wide.

At least nine buildings with over 30 apartments were destroyed.

The limited number of daylight hours in Norway at this time of year and fears of further erosion have hampered rescue operations.

The ground is fragile at the site and unable to hold the weight of rescue equipment.

The exact cause of the accident is not yet known but the Gjerdrum municipality, where Ask is located, is known for having a lot of quick clay, a material that can change from solid to liquid form. Experts said the type of clay, combined with excessive precipitation and the damp weather typical for Norway at this time of year, may have contributed to the landslide.

"This is completely terrible," said King Harald V after Norwegian royals visited the landslide site on Sunday.