Two teenage boys from the Aylsham area voluntarily attended the town’s police station on Sunday on suspicion of committing arson following a fire in Marsham.
The blaze, at a former chicken farm, started on Saturday morning and 40 firefighters – from Aylsham, Sprowston, Earlham, Carrow, Wroxham, Mundesley and Sheringham, together with the water carrier and control unit from Wymondham – spent all day fighting the fire. Some crews stayed overnight to make sure all the site was safe.
Nobody was hurt, but smoke billowed across the nearby A140, and motorists were urged to avoid the area.
The buildings have been derelict for several years, and police said investigations were ongoing.