Bunbury detectives are calling on assistance from the public as they continue to investigate an armed robbery in Dalyellup on Saturday, July 4.

In an online post, WA Police said at about 4am, an unknown male driving an SUV threatened two victims with a machete while they were seated at a bus stop on Parade Road.

They said the driver was wearing a balaclava at the time, while they believe the vehicle involved may have had a spare wheel mounted on the rear passenger side.

As they continue to investigate, an image has been released by the police of a silver Toyota RAV4.

Detectives are seeking to identify and speak with the vehicle’s occupants who may be able to help with the investigation.

Anyone with information relating to the incident or who recognises the vehicle is encouraged to contact Crime Stoppers online or by calling 1800 333 000.