On Friday (13) at 10.10pm, two crews from March, one crew from Chatteris and one crew from Whittlesey were called to a series of lorries on fire on Hostmoor Avenue, March.
Crews arrived to find five heavy goods vehicles well alight. Firefighters used four jets to extinguish the fires.
The crews returned to their stations by 1.03am.
The cause of the fires was deliberate. Anyone with information should contact police by visiting www.cambs.police.uk to submit an online report or call Crimestoppers on 0800 555111.