A large fire broke out on Monday night at the centre of Great Yarmouth in Norfolk.
Firefighters were still at the scene after 2200 BST, focusing on buildings in Alma Road in the centre of the resort town.
A spokesman for the fire service said: "The blaze is well set in a group of three-storey industrial units."
Fire crews and ten appliances from Yarmouth, Lowestoft, Acle, and from as far away as Wymondham and Thetford were sent to deal with the fire.
The spokesman said there were concerns about the fire spreading into the surrounding area.