Firefighters are issuing a safety reminder about smoking after a fire on Branch Road in Limehouse.
Parts of three balconies at a seven-storey block of flats were damaged by fire. There were no reports of any injuries.
The fire is being treated as accidental and is believed to have been caused by the unsafe disposal of smoking materials.
A London Fire Brigade spokesperson said: "We'd rather you didn't smoke at all, but if you are a smoker, it's absolutely vital you ensure your cigarette is completely out when you've finished smoking it.
"If you don't, you risk causing a fire which could not only destroy properties but also cost you your life."
The Brigade was called at 1545 and the fire was under control by 1649. Four fire engines and around 25 firefighters from Millwall, Shadwell, Whitechapel and Bethnal Green fire stations attended the scene.
Firefighters' smoking safety tips
· Use proper ashtrays, which can’t tip over and stub cigarettes out properly.
· Don’t leave lit pipes or cigarettes unattended.
· It's safer to smoke outside, but make sure cigarettes are put right out and disposed of properly.
· Don't balance cigars or cigarettes on the edge of an ashtray, or anything else – they can tip and fall as they burn away and cause a fire.
· Take extra care when you’re tired, taking prescription drugs or if you’ve been drinking alcohol.
· Always empty ashtrays carefully. Make sure smoking materials are out, cold and preferably wet them before throwing into a bin – never use a wastepaper basket.