At 3.35pm on Thursday (31) firefighters were called to a building fire on Longhill Road, March.
Crews from March, Wisbech, Chatteris, the North roaming fire engine and a water carrier from Ramsey are at the scene.
The fire involves a large workshop, two HGVs, cylinders and a diesel bowser. Firefighters are using hose reels and jets to extinguish the fire.
Longhill Road is currently closed while crews deal with the incident. People are advised to avoid the area.
Those living nearby are advised to keep their doors and windows closed due to the smoke.
There are no reported casualties.
Update - 8.30pm
The fire is now extinguished and crews are leaving the scene. It is safe to open windows if living in the immediate area of the fire.
Crews will be visiting the set regularly throughout the night to ensure the area is safe.
The cause of the fire was accidental.