Oslo-A suspect has been arrested after a woman was stabbed to death and two others injured in an attack in southeastern Norway, police said on Wednesday.

Officers said a 31-year-old man was being held on suspicion of murder and attempted murder, and he was thought to be the only perpetrator.

The suspect knew two of the victims, police said, adding that they were investigating whether his mental health was a factor in the attacks in three different locations in the city of Sarpsborg, south of Oslo. The husband of one of the victims told a local newspaper how the perpetrator had launched an attack in his house. “We were watching TV when we heard loud banging on the door. When I opened he tried to stab me, but I got away,” he said. The man then came in and cut his wife on the arm, the paper reported.

“The incident last night had a tragic outcome where one woman in her 50s died and another was seriously injured,” the police said.