Twelve people were evacuated from Peabody Square in Blackfriars Road in the early hours of Monday morning after a fire broke out in a first floor flat.
"When the brigade arrived there was a visible fire coming from the first floor of the building," said watch manager John Broadfield.
"The crews worked hard to put out the fire. They managed to contain it to the first floor and avoided it spreading to other properties."
Fire crews from Dowgate, Lambeth and Dockhead fire stations were at the scene.
The cause of the fire is under investigation.
At midday firefighters and a Metropolitan Police forensics team remained at the scene.