Norfolk Police are treating an agricultural building fire in Pulham Market as arson.
The blaze happened in Wood Lane, just before 10.30pm last night.
Appliances from Long Stratton, Harleston and the water carrier from Hethersett attended the blaze, which also involved a number of hay bales.
The fire crew from Long Stratton did not leave the scene until 3.15am this morning.
No one was reported to have been hurt in the incident
Police are appealing to anyone who witnessed the incident or anyone who may have information to call 101.