THE cause of a barn fire involving a tractor last night (Mon) is currently under investigation. Fire fighters were called to the scene on Old Bideford Road on the outskirts of Barnstaple at around 10.55pm. The galvanised barn measuring 10m by 5m was well alight when the crews arrived the scene. A police spokesman said the fire was believed to be of doubtful origin and officers were investigating possible causes including arson. Crews used two hose reel jets to battle the blaze, which destroyed a tractor and various other machinery. The fire was put out and officers returned to base at 1.10am.