A man is in hospital with a serious head injury after being assaulted in Broadfield, Crawley.
The assault on the 35-year-old, from Horley, was reported to Sussex Police just before 4am today (January 23) while the victim was in East Surrey Hospital.
His injuries are not life-threatening.
A spokesman for Sussex Police said the assault happened in Seymour Road at the junction with Trefoil Road shortly before 10pm on Wednesday (January 22).
The attacker was described as white, aged between 12 and 16 and of slim build.
Anyone who saw what happened is asked to call Sussex Police via 101 or email email@example.com.
Witnesses can also call the independent charity Crimestoppers on 0800 555 111.