Police are investigating multiple reports of sexual assault incidents in Altona Meadows yesterday (1 October).
Investigators have been told a man on a black electric bike rode past three women as they were walking along the Skelton Creek Trail between 3.30pm-4pm.
The unknown male sexually assaulted the women before riding off.
No words were exchanged but the male did look back at all three victims and is described as having a slim build, tall, and aged in his early 20s.
He was wearing a face mask, dark pants, jumper and a black motorbike helmet.
Anyone who witnessed the incident or with any information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au