The reports said the incident occurred around 7:30 am local time in Trangsund of Huddinge Municipality, located south of Stockholm, Xinhua reported.
The condition of the teenager remains unclear, but according to the police, the victim was conscious and able to speak when officers arrived at the scene. The teenager was transported to the hospital by ambulance.
One person has been arrested in connection with the crime. Police spokesperson Helena Bostrom Thomas confirmed that authorities are not searching for any additional suspects, and no further injuries have been reported.
The shooting occurred at a large primary school with approximately 700 students. The police have not released details about the exact location of the shooting or whether it took place inside or outside the school.