Firefighters are warning smokers to dispose of cigarettes carefully after a fire at an accommodation block on Repository Road in Woolwich.
Most of a plant room on the roof of a three-storey block was damaged by fire. There were no reports of any injuries.
The fire is believed to have been accidental and 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 your home, but also cost you your life.
"This incident is also a timely reminder to ensure you have working smoke alarms. A person was alerted to the fire when they heard a fire alarm sounding in an adjacent building. On investigation they saw smoke and flames coming from the roof.
"You should have working smoke alarms in every room where a fire can start, plus a heat alarm in the kitchen. They should be tested regularly."
The Brigade was called at 1723 and the fire was under control by 1813. Four fire engines and around 25 firefighters from East Greenwich, Eltham and Greenwich fire stations attended the scene.