Two cars were deliberately set on fire with the flames then spreading to three nearby garages.
The Dogsthorpe fire crew were called to the fire in Mountbatten Way, Ravensthorpe, at 2.08am this morning.
Wearing breathing apparatus they extinguished the fire using a hose reel before returning to their station.
Anyone with information about the fire should contact police either by calling 101 or by visiting www.cambs.police.uk to submit an online report.
Alternatively, call Crimestoppers on 0800 555111.