Police are investigating the circumstances surrounding an assault on a Mooroolbark-bound train on 16 December.
It is believed three offenders approached the victim between 1.40am and 2am and assaulted them.
The incident occurred between Ringwood Station and Mooroolbark Station.
The victim sustained minor injuries in the incident.
The offenders are described as being between 14 and 16-years-old, and were wearing hoodies. It is believed a female offender was also wearing glasses.
Police are urging anyone who may have witnessed the incident, or who may have been in the area at the time, to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au
