According to information from the school administration and the local police chief in Helsingborg, the injured person is an adult, writes Helsingborgs Dagblad .
The injured person was awake and able to speak in connection with the incident and the police expect to be able to conduct interviews at the hospital.
It is unclear what was behind the stabbing, which was carried out indoors.
The boy we suspect of this had left school. He was found outside the school grounds and taken into custody, says police spokesperson Leif Fransson.
The boy himself waved to a police car as it drove by and identified himself. He has been taken to the police station.
He is allowed to sit outside in public areas with an adult while waiting for the guardian and social authorities to arrive before we can talk to him, says Leif Fransson.
Parts of the school were initially cordoned off while police investigated whether more perpetrators were involved.
The knife has been seized.
