Eight fire engines and around 60 firefighters were called to a fire at a flat on Forty Acre Lane in Canning Town.
Half of a four-roomed flat on the 12th floor of the building was damaged by fire. Around 150 residents left the building before the Brigade arrived. Three women and two men were treated on scene by London Ambulance Service crews. One man was taken to hospital after suffering from smoke inhalation.
The Brigade's 999 Control Officers took 40 calls to the fire.
The Brigade's Fire Investigators believe the fire was caused by smoking materials.
Station Commander Jim Smith, who was at the scene said: "Fires caused by smoking materials including cigarettes, roll-ups, cigars and pipes, result in more deaths than any other type of fire. Stub cigarettes out properly and always dispose of them carefully.
"Make sure smoking materials are cold before emptying ashtrays. Preferably wet stubs before throwing them into a bin.”
Firefighters' smoking safety tips
The Brigade was called at 1822 and the fire was under control at 1945. Fire crews from Plaistow, Poplar, East Ham, Stratford, Millwall, Shadwell and surrounding fire stations were at the scene.