A woman has died and two more have been injured after a series of late night stabbings in Norway.

First reports of the attacks came in just before midnight in the city of Sarpsborg, south of the capital Oslo.

Police have arrested a 31-year-old Norwegian citizen who has a criminal record.

A press release said the attacker had a relationship with two of the women, although not with the woman who was killed.

The victim was in her 50s, police said. Another woman was seriously hurt while a third suffered lighter injuries.

Police said they were investigating whether the perpetrator’s mental health was a factor in the attacks.

Local media reported armed police, helicopters and nine ambulances were deployed early in the morning in Sarpsborg.

Officers locked down the city centre and asked residents to stay indoors via Twitter.

One woman was stabbed at the central bus station while waiting in her car.

Another was stabbed in her own home.

“We were sitting watching TV and there was a knock at the door. When I opened it he tried to stab me, but I got away,” her husband told local newspaper Sarpsborg Arbeiderblad. His wife was then stabbed in the arm.

One of the victims recognised the attacker, which led to his arrest at his home address.

One resident, Ole Martin Gilde, said he witnessed the arrest.

“The police blocked off the street, and I counted up to 12 police cars here,” he told Verdens Gang newspaper. “I also saw up to 10 armed police officers at the intersection here, and then they searched with a dog in all the backyards.”

Police have launched a full investigation and have appealed for witnesses to come forward.