More than £25,000 of damage was caused to cars and property after five arson attacks in just one night.
The fires broke out in Saltburn early on Saturday, shortly after a group of youths was spotted nearby.
In the first attack, a chair and two wheelie bins were set alight in Bath Street. Minutes later a Fiat Punto was in flames in Hilda Place.
Householders are being urged not to leave bins in alleyways and to bring them into their yards or driveways.
In another attack, a garage collapsed on to parked cars in Exeter Street after flames from four burning wheelie bins spread to the building.
Det Con Sue Moore, leading the investigation, said, "These fires have been started deliberately, and in one case if the fire had not been extinguished so quickly there would have been a real possibility that someone may have been seriously injured.
"I urge householders not to leave their wheelie bins in alleyways, but to take them into the yard once it has been emptied."