The landslide hit a residential area in the municipality of Gerdrum, about 30 km north of the capital, Oslo. Police said more than 900 people have been evacuated from the area.
Police said rescue workers continued to search the area for children and adults who feared they were caught in the mud and debris.
“We are pretty sure that there are people in the affected area, but we don’t know if all 11 people are there or if the number is lower,” police spokesman Roger Petersen told a news conference.
“We are still looking for survivors,” he said.
The photos of the site showed a large crater with destroyed buildings at the bottom. Television footage showed other buildings hanging on the edge of the crater. NRK broadcaster reported that two other homes collapsed into the pit on Wednesday afternoon.
Norwegian King Harald said the landslide made a deep impression on him.
“My thoughts are with all those affected or injured or who have lost their homes and who are now living in fear and uncertainty about the full extent of the disaster,” the 83-year-old monarch said in a statement issued by the king. palace.
Helicopters continued to fly over the area as night fell, sometimes dropping emergency responders toward the wreckage of collapsed homes.
“There may be people trapped … but at the same time we cannot be sure that it is the New Year’s holiday, which means that people could be elsewhere,” Prime Minister Erna Solberg told reporters after visiting the site.
Locals talked about their experience.
Oeystein Gjerdrum, 68, told NRK, “There were two tremendous jolts that went on for a long time and assumed snow had been cleared or something like that.”
“Then suddenly the electricity went out, and a neighbor came to the door and said we need to evacuate, so I woke up my three grandchildren and asked them to get dressed quickly.”
At a press conference, Toriel Hofchagen, regional head of the Norwegian Directorate of Water Resources and Energy, said land masses were still moving in one of the biggest mudslides in Norway’s modern history.