On Monday (27) at 6.53pm, one crew from St Ives and one crew from Ramsey were called to a building fire at RAF Upwood.
Crews arrived to find a fire in a derelict building on the site. Wearing breathing apparatus, firefighters used one hose reel to extinguish the fire, before returning to their station by 7.37pm.
The cause of the fire is believed to be deliberate. Anyone with information should contact police by visiting www.cambs.police.uk to submit an online report or call Crimestoppers on 0800 555111.