Thirty firefighters were required to deal with a blaze at Metcalfe Court in Greenwich Millennium Village on Wednesday afternoon.
The fire started in a fifth floor flat and then spread to an apartment in the floor above, causing damage to both.
Six appliances were at the scene after the Fire Brigade were called at 2.30pm. Firefighters from Poplar, East Greenwich, Woolwich, Silvertown, Plumstead and surrounding fire stations had the fire under control two hours later.
Nobody was injured in the fire and the cause is currently under investigation.