Four fire engines and around 25 firefighters tackled a flat fire on Wallwood Street in Poplar.
Part of a five-roomed flat on the second floor of the building was damaged by fire. Firefighters rescued two men from a second-floor balcony via a nine-metre ladder. They were taken to hospital by London Ambulance Service crews.
The cause of the fire is believed to have involved lithium-ion batteries for an e-bike.
A London Fire Brigade spokesperson said: “Lithium-ion batteries are susceptible to failure if incorrect chargers are used and there is a significant risk posed by e-bikes which have been converted.
“Another issue with fires involving lithium-ion batteries is that when they fail, they eject their contents over a wide area which can lead to multiple areas of burning in the room where the fire has started.
“Our advice is to try and store and charge these items in a safe location if possible, such as in a shed or garage, and if they have to be stored inside, make sure there is smoke detection fitted and your means of escape is not obstructed.
“However, we know this won’t be possible for everyone, so if you are charging them indoors, please follow our advice on using safe charging and ensure everyone in your home knows what to do in the event of a fire.
“Make sure they are charged in a room where there is smoke detection and on a hard, flat surface.
“We would also suggest people try not to charge them when they are asleep, so that if there is an issue they can react quickly.”
The Brigade was called at 0753 and the fire was under control by 0856. Fire crews from Poplar, Millwall, Bethnal Green and Shadwell fire stations attended the scene.