The fire at the Fresh Catch processing plant in Peterhead sent dark plumes of smoke across the Aberdeenshire town and saw nearby homes evacuated.
At its peak 10 fire units and several specialist crews tackled the flames at the industrial site in Kirk Square yesterday.
Three crews remained on scene overnight to damp down the fire before investigators assess the damage and potential cause later, while police asked people to stay away from the scene.
A rest centre was set up at Peterhead Academy for people evacuated from their homes in Errol Street and road closures were expected to remain in place for some time.
Fresh Catch is owned by Northbay Pelagic in the north-east town of Peterhead, one of Europe’s busiest fish landing ports. The company is reported to employ around 300 people.
Emergency services were called to the blaze just before 3pm yesterday and did not stand down until just before 1am when they had managed to get it under control.
Banff and Buchan SNP MP Dr Eilidh Whiteford said last night: “Thankfully Police Scotland say there no reports of casualties but homes have been evacuated and the priority now is everybody’s safety.
“This will be a very uncertain time for the workforce and, once the extent of the damage is known, we will be in a better position to assess what kind of assistance might be required.”
Aberdeenshire Council tweeted last night: “A number of roads around Peterhead town centre are closed and are likely to remain closed into Sunday.
“We would like to thank all emergency service personnel involved in tackling today’s fire in Peterhead and keeping people safe.”