Four fire engines and around 25 firefighters were called to a fire at a block of flats on Priory Road in East Ham.
A balcony on the second floor of an eight-storey block was damaged by the fire. A woman and two children left the affected property before the Brigade arrived. There were no reports of any injuries.
Sub Officer Jayvin Patel, who was at the scene, said: "The balcony was well alight when crews arrived on scene.
"Firefighters attacked the blaze from the outside and stopped the fire spreading into the flat."
The Brigade's 999 Control Officers took nine calls to the blaze.
The Brigade was called at 0259 and the fire was under control by 0420. Fire crews from Plaistow, East Ham, Stratford and Poplar fire stations were at the scene.
The cause of the fire is under investigation.