The fire service was called to attend a blaze at a derelict building in Hove.
East Sussex Fire and Rescue Service said it was called at 3.58pm on Sunday (March 24) to reports of smoke coming from the building in School Road.
The fire service said four fire engines and an aerial ladder platform remained left the scene at 5.20pm confirming the fire was out.
The fire service said the fire is being treated as suspicious.
A spokesman said: “Crews are using breathing apparatus, two main jets and two hose reel.”
The fire is now out, the fire service confirmed at 5.45pm.
There were no reports of injuries.
A fire spokesman added: “Good work by crews to stop it spreading – leaving scene now.”