One woman died and two others were injured after a series of stab wounds in the night in Norway.
The first reports of attacks arrived just before midnight in the city of Sarpsborg, south of the capital, Oslo.
Police arrested a 31-year-old Norwegian citizen who will be interviewed today.
A press release said that the alleged male abuser had a relationship with two of the women, but not with the woman who was killed.
The victim was in his 50s, police said. Another woman was seriously injured while a third suffered lighter injuries.
The arrested man will be charged with murder and attempted murder, the statement said.
Police said they were investigating whether the mental health of the alleged abuser was a factor in the attacks. The press release said the man arrested had a history of violence, but at a later press conference, police said it was not.
Local media reported that armed police, helicopters and nine ambulances were deployed early in the morning to Sarpsborg.
Officers locked the downtown area and asked residents to stay inside via Twitter.
A woman was stabbed at the central bus station while waiting in her car.
Another was stabbed in her home. “We were sitting in front of the television and there was a knock on the door. When I opened it, he tried to stab me, but I ran away, ”her husband told local newspaper Sarpsborg Arbeiderblad. His wife was then stabbed in the arm.
One of the victims recognized her attacker, which led to the arrest at the man’s home.
A resident, Ole Martin Gilde, said he witnessed the arrest.
“The police blocked the street and I counted up to 12 police cars here,” he told the Verdens Gang newspaper. “I also saw up to 10 armed police at the intersection here, and then they searched with a dog in all the backyards. ”
Police have asked for witnesses to come forward.