More than 40 firefighters were called to tackle a blaze at a shellfish factory at King’s Lynn docks.
The fire broke out in a workshop at Lynn Shellfish at Alexandra Dock on Wednesday at around 12.30pm.
People were urged to stay away from the area and close their windows.
Crews from Lynn, West Walton, Downham Market and Methwold were at the scene until around 11.20pm.
The environmental protection unit, aerial ladder platform, police drone, command support unit and technical rescue vehicle were also involved in the operation.
Norfolk Fire and Rescue group manager Terry Pinto said: “We had more than 40 firefighters on scene at this commercial building fire, which has now been extinguished. We scaled back the 200m exclusion zone in the evening.
“We are now working with the site owners and Environment Agency, and maintained a presence on scene into the night.”