At around 11.25pm on Friday (July 7) emergency services were called to the incident in Grove Road.
The blaze destroyed a caravan, damaged a vehicle and a fence, along with surrounding trees.
Police Constable Steven Wallace said: “The fire is being treated as suspicious, and we are appealing for anyone with any information to come forward.
“I would ask anyone with doorbell camera footage or private CCTV to get in touch; you may have captured something that can assist our enquiries.
“Anyone with any information is asked to contact Police Scotland on 101, quoting 4733 of Friday, 7 July, 2023.”