Six fire engines and around 40 firefighters tackled a fire in a maisonette at a block of flats in Pier Street, Isle of Dogs.
Part of the first floor of a split level maisonette, on the seventh and eighth floor, was damaged by fire.
The Brigade was called at 1616 and the fire was under control by 1734. There were no reports of any injuries.
Fire crews from Millwall, Plaistow, Shadwell, Whitechapel and surrounding stations were at the scene.
The cause of the fire is under investigation.