About 60 fire-fighters are battling a large blaze at an engineering factory in Thetford.
Norfolk Fire and Rescue Service was called to the incident, in Burrell Way at about 3.44pm and 25 per cent of the building which has a paint shop is involved in fire.
Seven fire engines are at the scene as well as a water carrier, environmental protection unit, control unit and aerial ladder platform.
Norfolk Police are assisting the fire service and a 150 metre cordon has been put in place.
There are local road closures and some businesses have been evacuated as a precaution.
No residential properties have been evacuated at this time.
Motorists and the public are being advised to avoid the area while emergency services deal with the incident.
More details to follow.