Firefighters were called to a fire at a flat on Bridge Walk in Deptford.
A small part of a five-roomed flat on the fifth floor of the building was damaged by fire. There were no reports of any injuries.
The residents of the flat were alerted to the fire when they heard a bang coming from the hallway and the electricity went off. On investigation, they could smell burning and discovered the fire in a storage cupboard.
The electricity supply was isolated by an on-site electrician and firefighters checked for fire spread behind the plasterboard walls and ceiling.
The Brigade was called at 1146 and the fire was under control by 1314. Five fire engines and around 35 firefighters from Deptford, Greenwich, New Cross, East Greenwich and Lee Green fire stations attended the scene.
The fire is believed to have been accidental and caused by resistive heating in the consumer unit.