Up to 25 firefighters were called to tackle a blaze at a four storey building in south Belfast.
The blaze broke out at Doorsteps sandwich shop on Botanic Avenue just after 6am this morning.
A store room on the ground floor was badly damaged but the fire was quickly brought under control.
Aidan Jennings, Northern Ireland Fire and Rescue Service (NIFRS) group commander, said the swift actions of his officers prevented further damage to the property.
Mr Jennings said it was too early to say how the fire started.
“We have no cause determined as yet but a full fire investigation is under way,” he said.
Botanic Avenue has been closed at its junctions with Cromwell Street and Lower Crescent.
A number of bus services in the area have been disrupted and the closure is likely to have a knock-on effect on rush hour traffic travelling into the city centre.
NIFRS said two fire crews are expected to remain at the scene until at least 9am.