The new fire, on the island of Frøya in South Trøndelag county, broke out hundreds of kilometres south of Flatanger municipality, where firemen have been fighting blazes around two historic villages since Monday night.
"Police are now evacuating people in the Sandvika area," the county police said in a press statement issued at 3pm. "The fire is not under control, and efforts to extinguish it are still continuing. In addition to the fire crews on the ground, there are five helicopters in the area to assist putting out the fire. Many of these have come directly from the operation at Flatanger."
According to VG newspaper, 300 people have already been evacuated as police fear the fire could envelop the main village on the island.
The mayor of Flatanger said at a press conference at 1pm that firefighters had finally put out the fire that ravaged two historic coastal villages in his community throughout Tuesday.
"We have very positive news in that it looks as if the fire is extinguished," Mayor Olav Jørgen Bjørkås said as he opened the press conference.
The fire destroyed about 90 buildings in the coastal villages of Hasvåg and Småværet, and forced the evacuation of 33 residents from the area.
Northern Norway has seen an unusually dry period, with no rain since December, which, combined with the intense cold, has had the effect of freeze-drying the vegetation, making it extremely vulnerable to fire.
On Wednesday, Norwegian authorities started warning people against lighting fires outside, or even leaving candles at the graves of relatives.