The suspect, who was arrested last night and has been questioned, is a 37-year-old Danish citizen.
He is accused of murdering five people – four women and one man – and injuring several others last night in the town of Kongsberg, which is near the Norwegian capital of Oslo.
Those killed in the attack were all aged between 50 and 70.
Police were alerted to the attack and confronted the attacker at 18:12 (CEST), six minutes after the attack begun. However, the attacker escaped this first confrontation, and was not caught by Norwegian Police until 18:47, 35 minutes after the attack started.
Regional police chief Ole Bredrup Saeverud said that all five victims were likely killed in the time between the first face-off with police and his capture.
An off-duty police officer was injured in the attack. The officer and another injured individual are both currently recovering in hospital with non life-threatening injuries.
Police believe the attack began inside a Coop Extra supermarket on the west side of Kongsberg.
After his arrest, the suspect was taken to a police station in Drammen, a city which is a 40 minute drive from Konsberg.
The suspect’s defence lawyer, Fredrik Neumann, said his client was questioned for more than three hours and was co-operating with authorities.
Neumann also said that the suspect had a Danish mother and Norwegian father.
Kari Anne Sand, the major of Konsberg, said: “This is a shocking event that we scarcely believed could take place in Norway.”
Prime Minister Jonas Gahr Store, who assumed office today, spoke to the press last night and said: “What we have heard from Kongsberg tonight testifies that a cruel and brutal act has been committed.”
His predecessor, Erna Solberg, who was still the Prime Minister when she spoke last night, said: “The news is gruesome. The events shake us. I understand that many are afraid. That is why it’s important to emphasise that police are in control.”