A 16-year-old boy was indecently assaulted moments after being robbed in Leicester on Wednesday evening.
The teenager was approached by three men in Humberstone Gate and led into St James Street where his mobile phone and other belongings were stolen.
The offenders then left the scene before one man returned and led the boy to Crafton Street East where he was indecently assaulted.
All three were black, in their early to mid 20s and wearing dark clothing.
Det Con Amanda Lane said: "This was a traumatic incident for the victim, which has left him extremely shocked and distressed.
"We believe that the victim and offenders passed several people while they were walking to St James Street and the St Matthews Estate and I would like to hear from anyone who may have seen them."