Norwegian police are still investigating the motive behind the bow and arrow attack. (Photo: Getty Images)

Investigators named the suspect as Espen Andersen Braathen, a 37-year-old living in the Kongsberg municipality where the attacks took place on Wednesday evening.

Police had been concerned about signs of radicalisation in the suspect before the attacks, carried out with a bow and arrow and other weapons, a senior officer said.

Flags flew at half-mast across Kongsberg after the deaths of four women and a man, all aged between 50 and 70. Three others, including an off-duty police officer, were wounded.

Police said the suspect had a history of being "in and out" of health institutions.

They added that the method of the attackwas similar to many politically motivated attacks carried out in Europe in recent years.