The brawl took place outdoors shortly after midnight and according to the police, many people were at the scene.
- We choose not to specify what type of shelter it is about, says Dennis Johansson Strömberg, press spokesperson at the police.
Two men, in their 20s and 40s, were arrested by police and later arrested by prosecutors.
They are both suspected of aggravated assault.
Several interrogations with witnesses have been held during the night.
The injured boy was taken to hospital by ambulance.
SVT currently has no information about his health condition.