Pictures released by Norfolk Police show the extent of the damage to a farm building after nearby straw bales were deliberately ignited in Stratton St Michael last month.
Emergency services were alerted to a farm off Church Lane on Thursday, March 31, where a stack of bales had been ignited.
The fire spread to a large chicken shed, which did not contain any livestock, and was completely destroyed.
Two boys from the Long Stratton area, have been arrested in connection with the incident, as well as another which took place on March 30.
Sometime between 8.30pm and 9.15pm at the junction of Manor Road and Flowerpot Lane, Long Stratton, police officers received reports a bin had been deliberately set on fire at a bus stop.
The boys, aged 12 and 13 and cannot be named for legal reasons, have been released on bail and will return to Wymondham Police Investigation Centre on June 2.
Anyone with information on the two incidents is asked to contact police on 101.