Four fire engines and around 25 firefighters were called to a fire at a disused shop with flats above on Tower Bridge Road in Southwark.
Flats on the first and second floor were damaged by the fire. There were no reports of any injuries.
The Brigade was called at 0257 and the fire was under control by 0446. Fire crews from Dockhead, Old Kent Road, Dowgate and Whitechapel fire stations attended the scene.
The cause of the fire is under investigation.