Senior Sergeant Anthony Bond, of Dunedin, said emergency services attended the fires on Sunday, both about 12am.
One fire was located at Marlow Park in John Wilson Ocean Dr and the second was near the back of the BP petrol station in Andersons Bay Rd.
A Fire and Emergency New Zealand crew from St Kilda extinguished the blaze at Marlow Park, while crews from the Dunedin and Lookout Point stations put out the blaze behind the petrol station.
Both fires were being treated as suspicious and being investigated by Dunedin police, however there were currently no lines of inquiry.