Dunedin CIB are investigating three fires in the area during the past week.
Firefighters were called to a blaze in which an Atomic Shuttles bus had been set alight outside the Ocean Beach Hotel in St Kilda last Wednesday, and detectives were alerted to two nearby car fires overnight on Saturday.
Detective Sergeant Chris Henderson said police urged residents to be vigilant following the fires.
"They are in close proximity. We believe they are all related. We want people to be vigilant that their cars are locked and report any suspicious circumstances to police.''
The first car fire occurred in Jackson St, about 500m from the Ocean Beach Hotel, while the second was in nearby Bird St.
Police have called for the person who raised the alarm over the bus fire to come forward.
"There was a person that saw the Atomic Bus shuttle and raised the alarm and ran into the pub,'' Det Sgt Henderson said.
"We don't know who he is, so we would like him to come forward. He was gone by the time police arrived.''
Police could not comment on the cause of the blazes.
It appeared the cars were entered and the fires started inside; similar circumstances were reported in the blaze which tore through the shuttle bus.
Anyone with information about the fires, or the identity of the person who reported the bus blaze, should contact Dunedin police. Information could also be given anonymously to Crimestoppers.
Suspicious activity should be reported immediately on 111.
• Dunedin police (03) 471-4800, Crimestoppers 0800 555 111.
