A 14-year-old boy suffered a broken jaw when he was punched in the head as he walked home at lunchtime.
He was walking in Manzil Way, Oxford, at 1.45pm on Friday when a man in his late teens punched him several times.
Passers-by tried to intervene and the boy required hospital treatment.
Police say the attacker was described as Asian, slim and 6ft tall and was wearing an army-style camouflage jacket.
Anyone who saw the assault is asked to contact Dc Richard Allmond from Oxford Force CID on 101.
See on www.oxfordmail.co.uk