According to police reports, the victims received injuries to their torsos, and were taken to hospital. Three are women, all under twenty, and one is the school janitor in his early twenties. All were in a stable condition on early Thursday evening.
One of the victims is reported to be more seriously injured, and had surgery immediately following the attack. This person is now in intensive care.
It seems that the victims were stabbed inside the school, two in the school canteen and two in the lobby.
The police have examined the school, and no more victims have been found.
The police have apprehended the 16-year-old perpetrator, also a student at the school. The boy has admitted the stabbings, but the motive for the attack is not yet known.
Early Thursday evening Oulu police were preparing to interrogate the suspect – who, up to then, was too worked up for talking.
The police expect to complete their investigation by the end of Thursday, and said they would report on more details as they emerge. The interrogation of the suspect is to go on longer.