Three vehicles were found in flames in a Pāpāmoa East street early this morning.
Both police and Fire and Emergency have labelled the incident "suspicious" and launched investigations.
Firefighters were called to the fires in Kanapa Close, Papamoa East at 2.37am, with police called to assist about 20 minutes later.
Fire and Emergency Northern Communications shift manager Craig Dally said a fire investigator was looking into the incident.
A police media spokesman said a scene guard was in place from 5am. Police were making inquiries.
A Golden Sands resident said it looked like two cars and a van had been burned near a new house build in the cul-de-sac.
The scene was cordoned off with tape.
Elsewhere in the Bay of Plenty, no one was injured in a garage fire in Rotorua.
Firefighters were called to Utuhina at 1.30am and found the Kahu St building "well-alight", Dally said.
Earlier that night, about 9pm, firefighters were called to a report of smoke in the ceiling of another house in Utuhina.