Police believe a young boy could have been involved in attacking a vulnerable man in Northampton.
The assault happened at about 10.20pm on Monday in Dallington Brook, Northampton.
Nothing was taken from the man, but he was left needing hospital treatment after being attacked from behind.
It is not known how many people the man was assaulted by, but one of them may have been a young boy.
Anyone who knows anything about the incident can call Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.