A "significant fire" at a shellfish factory in King's Lynn port is under control after several fire crews battled the blaze.
The blaze broke out at a workshop at Lynn Shellfish in Alexandra Dock at about 12.30pm, and caused "substantial damage" to the building.
A 200m cordon was put in place and locals were advised to avoid the area keep their doors and windows closed. A smaller cordon remained in the area while work was completed to make the scene safe.
Several fire crews, police and ambulance services were called out, as part of a multi-agency response.
Tackling the fire was complicated by the presence of gas cylinders in the workshop, which posed a risk of explosion.
Firefighters used compressed foam to get the blaze under control.
Everyone working at the factory managed to escape the building safely.
Terry Pinto, group manager for Norfolk Fire and Rescue Service said: "When we arrived it was a significant fire. There was lots of thick black smoke in the area coming from the building.
"Initially we couldn't establish whether everybody was out of the building and we were waiting for roll calls to be completed.
"We treated the incident as though people were reported missing but luckily everyone managed to get themselves out to safety, which was established within the first 20 minutes of our arrival.
"The nature of the fire posed some problems as it involved acetylene cylinders, which pose a significant hazard to us and required us to mobilise lots of resources.
"It's been a really big multiagency effort which helped us to resolve the incident quickly."
It took two hours to get the fire under control and fire services are to remain at the scene into the evening to make sure the scene is safe.
Six fire engines, a command unit and an environmental protection unit attended and drones were also employed by the police.
Mr Pinto added: "There is significant damage to the building but it should not pose lasting damage to the business.
"We'll be temperature checking for a while to make sure the gas cylinders no longer pose a risk.
"We will be working closely with the business and port to establish a cause and will be carrying out our own fire investigation when the scene is safe to access."
The fire delayed the fishing fleet working in the area for the day, with several boats stuck out in the river for several hours.
Mr Pinto said: "We've now opened the waterway so they can come back in.
"We've been working closely with them and they have been patient while we continued our work."
Neil Lake, director of John Lake Shellfish, which is situated nearby, said: "It stopped our factory dead. We couldn't get catches of our boats and we couldn't move forwards or backwards.
"It couldn't have happened at a worse time as there is only a three hour window either side of high tide to get our boats in and out. The boats were coming back in to drop off their catch and get back out again but weren't able to.
"Everything was delayed and we had men waiting to grade shrimp, a lorry loaded and produce waiting to be certified for export but no one could get in or out.
"It has been a complete nuisance but of course these things happen."
A resident living opposite the port, who did not want to be named, said: "I saw all the fire engines go past but didn't know where they were going.
"There was an awful lot of fire engines and police coming down.
"With it being a working port, there is always lots going on."
Another person who works nearby said: "I heard all the sirens but didn't see anything, or any smoke."
Norfolk Fire said at 4.20pm that it was safe to re-open windows and doors near the area.
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