A large landslide struck a small town in southeastern Norway, burying homes and leaving several people missing, police and local media said on Wednesday.

Estimated to be 700 meters (2300 ft) long and 300 meters wide, the landslide created a huge crater.

What we know so far

Police were alerted to the landslide in the town of Ask, around 40 kilometers (25 miles) north of Oslo, at 4 a.m. local time (03:00 GMT/UTC).

• Emergency services, the military and the Red Cross are assisting the rescue effort.
• At least 10 people were injured, with one being transferred to Oslo with serious injuries.
• More than 20 people are unaccounted for.
• At least 700 people were evacutaed to a nearby hotel to be registered and offered assistance.

The landslide caused power outages, impacting 495 residents, according to Norwegian public broadcaster NRK.

What the authorities have said

"Police are designating this as a disaster," search operation chief Roger Pettersen told NRK.

Emergency calls had come in from people in the Gjerdrum municipality, home to 5,000 people, saying their whole house was moving, Pettersen said. "So there are dramatic reports and the situation is serious."

"Conditions are challenging. It is dark and the weather is bad," Pettersen said.

Norwegian rescue group Norsk Folkehjelp Follo said they had sent a total of 40 crew and 9 emergency ambulances to assist with search and rescue efforts.

How has the government reacted?

Norway's Prime Minister Erna Solberg offered her sympathies, saying: "It hurts to see how the forces of nature have ravaged Gjerdrum [the wider municipality]. My thoughts go to everyone affected by the landslide."

"This should have been a New Year's weekend where we should have had peace and quiet and maybe should have worried most about COVID-19 and not whether we have missing persons from a landslide," Solberg told Norwegian broadcaster TV2.

"It is a catastrophe," she told reporters after visiting the site.

What caused the landslide?

The area where Ask is located is known for having a lot of so-called quick clay — a form of clay that can change from solid to liquid form. 

Masses of earth were still moving in what has been one of the biggest clay slides in recent Norwegian history, Torild Hofshagen, the regional head of the Norwegian Water Resources and Energy Directorate, said at a press conference.

Southern Norway has seen large amounts of precipitation in recent days, which may have caused the clay soil prevalent in the area to shift.

kmm, ab/rt (dpa, AFP, Reuters)