Police said on Friday they have arrested a teacher on suspicion of assaulting a student.

Officers said a 57-year-old man allegedly hit a 15-year-old at Tai Po Sports Ground on Wednesday as the school held its sports day.

The man was arrested on suspicion on assault occasioning actual bodily harm.

The force said the teenager's mother called the police, and that he received treatment for a hand injury in hospital.

The suspect has been released on bail and will report back to the police next month.