The alarm about a larger brawl at Borgmästaregården came at 15 o'clock on Friday.
According to witness statements, it was a group of young adults, says the police's press spokesperson Patric Fors.
The injured boy is in his 15th year, according to Patric Fors. A tool has been used, but what kind he does not want to comment on.
In the evening, Region Skåne announced that the boy has serious injuries.
An area was cordoned off for a technical investigation. No suspect has been arrested.
