Just prior to the attempted suicide, bullies had bound the boy onto a set of wall bars with a jump rope and left him there, according to the incident report filed by the school's principal with the Swedish Work Environment Authority (Arbetsmiljöverket).
The boy then attempted to hang himself with a gym bag in the locker room.
The incident is very serious, said Lars Rejdnell, child and youth director of the municipality of Linköping.
"It is obviously completely unacceptable that this has happened. This is a small school in a small town and what has occurred is extremely deplorable," he told the the local Norrköpings Tidningar newspaper.
The matter has been reported to the police and investigations have been carried out by both the school and the municipality, according to Rejdnell.
Students have received support from the school psychologist, student health team and regional child and youth psychiatric health services.
The school has also called for a meeting with parents. Rejdnell is satisfied with how the school's leadership acted following the incident.
"From what I can see, they have done everything they should. After everything that has happened, they have reacted in a good way," he said.
According to Rejdnell, the boy had not been bullied in the past.
"As it has been described to me, this was an isolated event. The boy is back in school and coping very well," he said.