The 52-year-old teacher at Segervångs School was left with a bloodied face after the assailants, armed with knuckle dusters, burst into the class mid-lesson at 11.30am. The attack occurred after the men said the teacher’s name and asked him to confirm his identity, newspaper Sydsvenskan reports.
The attackers left the scene with the teacher hot on their heels. With the aid of passers-by, the teacher was able to detain one of the men until the police arrived and placed him under arrest.
The 21-year-old attacker has a previous record for crimes that include robbery. Police are continuing to search for the two remaining assailants.
The teacher was taken to hospital to receive stitches.
“I find this incredibly unpleasant,” school principal Agneta Brisfors told Sydsvenskan.