Photo: The Border Mail

Investigators have been told two unknown offenders attended the Princes Highway service station about 7am on 10 February.

The pair threatened the attendant with handguns.

They then fled the scene on foot to Latrobe Street when they got into two separate vehicles.

The vehicles were a small white hatchback and a small red hatchback.

Detectives have released CCTV images of two persons of interest (with their cars), who they believe may be able to assist with their enquiries.

Anyone with information is urged to call Crime Stoppers Victoria on 1800 333 000 or log onto www.crimestoppersvic.com.au.