Firefighters from Blackpool and Bispham were called out to a suspected arson.
The crews fought a fire in a large out-building near flats at the corner of Nothumberland Avenue and Holmfield Road.
A Lancashire Fire and Rescue spokesman said they were still investigating the cause of the fire but believed it had been started deliberately. He said the alarm was raised by occupants of the flats but no-one was injured in the incident. Firefighters using breathing apparatus and a hose reel jet dealt with the fire.