Officers believe that three men are responsible for at least five separate armed robberies at service stations.
Detectives believe the crime spree started at a service station on Thompsons Road in Patterson Lakes on Sunday 3 August just after 8.30pm.
Two men entered the premises and threatened the attendant with a knife before demanding cash and cigarettes.
The pair then fled the scene with cash and cigarettes.
Investigators believe that the same trio committed a further four service station armed robberies at –
• Marine Parade, Hastings just after 7pm on 6 August
• Balcombe Road, Black Rock just after 10.30pm on 8 August
• Stony Point Road, Crib Point just after 8pm on 13 August
• Davey Street, Frankston just before 9pm on 17 August.
All of the armed robberies were similar in nature with cash and cigarettes stolen.
The offenders are described as Caucasian in appearance and aged in their 20s.
They were wearing black balaclavas at the time of the robberies.
Police have released images and CCTV of men that may assist with their enquiries.
Anyone who has any information about the incident, is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppers.com.au