The train, designed to carry loads of iron ore, derailed after it hit the moose on the tracks Monday evening.
"It must have been a monster moose," said Harry Korslund of the agency in charge of the rails, Jernbaneverket.
"It all depends, of couse, on how the train hit the moose, but in this case it was enough that it derailed."
The accident occurred between Dunderland and Mo i Rana. Passengers were being transported from Mo i Rana to Dunderland by bus in both directions.
Some trains from Mosjøen to Bodø were being replaced with busses along the entire route.
Railroad officials faced a major job clearing the rails and getting the trains back on track. Korslund said regular service wouldn't resume until Wednesday afternoon or evening.
