The islands' governor Kjerstin Askholt said that no one had been injured or killed in the event, which is the latest in a string of avalanches to hit the town.
“I didn't get any warning. There was a huge bang, and then the house started moving around,” one resident, Nils Lorentsen, told NRK. “There were crushed scooters and sledges lying up along the wall. The neighbour's car was pushed into the neighbouring apartment.”
Frank Johnny Olsen told NRK that four adults, including himself, and two children had been one of the houses as the avalanche hit.
Although his children had been “thrown around”, he said, "we didn't think it was serious because the electricity didn't even go off."
A total of 13 people were living in the two houses which were destroyed, and an additional 75 houses were evacuated.
According to the local Svalbardposten newspaper, between 100 and 150 people were rapidly on the scene with shovels and search equipment. Emergency vehicles and rescuers were also quickly on site.
Two people died and nine were injured when an avalanche hit Longyearbyen in December 2015.
Editor's note: a previous version of this article estimated a figure of 200 people for the number of evacuations. That has now been corrected to reflect the number of homes affected by the evacuation order.