Four fire engines and around 25 firefighters were called to a fire at a terraced house converted into flats in Gloucester Mews in Leyton.
A two-roomed flat on the first floor was damaged by the fire. There were no reports of any injuries.
The Brigade was called at 1521 and the fire was under control at 1616.
Fire crews from Leytonstone, Homerton, Stoke Newington and Tottenham fire stations are at the scene.
The cause of the fire is under investigation.