Four fire engines and 21 firefighters and officers were called to a flat fire in Whiston Road, Hackney last night.
Half of a third-floor flat and part of the wooden cladding surrounding a window was damaged by fire. A woman and two children from the affected flat left the building before firefighters arrived.
The most likely cause of the fire is believed to be a phone charger overheating on a bed.
London Fire Brigade spokesperson said:
"Thankfully the mother and children quickly escaped the flat soon after noticing the fire in the bedroom. Phone batteries can get extremely hot. Unplugging appliances and chargers when you are not using them or when you go to bed helps reduce the risk of fire."
Two women were led to safety by fire crews wearing breathing apparatus. Around 30 people left the property before the arrival of the Brigade.
The Brigade was called at 1833 and the fire was under control at 2012. Fire crews from Bethnal Green, Islington, Dowgate, and Shadwell fire stations attended the scene.