Police are investigating two armed robberies, including one in which a service station attendant was threatened with a metal pipe in Laverton North last week.

Police said a male offender attended a service station on Fitzgerald Road, Laverton North around 3.45am on Monday, October 21.

it is believed the same man attended a service station in Geelong Road, Brooklyn, about 10 minutes later.

It is believed the man travelled between the two locations in an unknown vehicle.

During each incident, the man produced a metal pipe and threatened the petrol station attendant, before making demands for cash and cigarettes.

Both attendants refused and the offender left each store empty handed.

No-one was physically injured during the incidents.

The male police wish to speak with is perceived to be Caucasian in appearance.

He was wearing an Oakland Raiders black hoodie, black Adidas shorts with white stripes down each leg, dark runners and a dark cap under the hood of his jumper.

Investigators are appealing for anyone who saw the man or with information to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au