The emergency services went to a burnt-out sheepfold in Vågå in Innlandet on Saturday afternoon.
Firefighters arrived at the scene shortly after 12 p.m., Innlandet Center 110 confirms to TV 2.
Chief operating officer for all Otterdalen fire services, Atle Festervoll, told TV 2 it was a major fire and extensive extinguishing work was underway.
– Everything is burning and the barn was on fire when we were warned, says Festervoll, who adds that the surroundings seem very dry.
There should be no risk of spread to the ground or other buildings, and there was no one inside the barn, according to police and firefighters.
Around 12:30 p.m., there were no reports of large flames in the area, but lots of smoke in the area.
– We need to put out the fire to make sure it’s safe and the fire can be contained, he said.
Police report that several hundred animals must have been inside the barn.
Innlandet Police District Director Andreas Ulshagen Jorde told TV 2 at 12:45 p.m. that the fire needs to be brought under control, but there is still work to be done to put it out.
– The barn is completely burnt down, and a lot of sheep have burned inside. We do not yet have an overview of the total number. A number of animals have been rescued, says Ulshagen Jorde.