A good Samaritan was punched in the face after stopping to see if a fallen cyclist was hurt.
The motorist was driving along Mickleburgh Hill in Herne Bay when he saw the youngster fall off his mountain bike near the junction with Margate Road.
He stopped his car and got out to see if the boy was injured, but was punched in the face by the teenager's friend.
The attacker – who was also on a mountain bike – is described as white, aged between 15 and 19, of slim build and about 5ft 10ins tall.
He was wearing a tracksuit or jeans. His friend was riding an old, dull grey bike.
Anyone with information about the attack at about 10.30pm on April 9 should call police on 101 or Crimestoppers anonymously on 0800 555111, quoting crime number ZY/9912/12.
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