Six fire engines and around 40 firefighters have dealt with a flat fire on South Quay Square in Canary Wharf.
Part of a flat on the seventh floor was damaged by fire.
The Brigade was called at 1502 and the fire was under control by 1528. Firefighters from Millwall, Poplar, Shadwell, Whitechapel, Bethnal Green and Dowgate fire stations are at the scene.
Fire investigators believe the fire to be accidental and due to a fault in an immersion heater.