Wayward Taskforce detectives are investigating after a boy was robbed and assaulted in Williamstown last week.
The 13-year-old was walking along Electra Street when he was approached by four male youths about 5pm on Saturday, 3 October.
The teens assaulted the victim and pushed him against a fence before stealing his phone and fleeing.
The offenders were later seen walking along Ferguson Street, Williamstown a short time later.
The victim was not physically injured during the incident.
Detectives have released images of four male youths they believe can assist with their enquiries.
Anyone with who recognises the youths or with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au