Four fire engines and around 25 firefighters were called to a fire at an underground car park on Weatherley Close, Poplar.
A member of the public saw smoke and called 999. Three cars were destroyed by the fire. There were no report of any injuries.
The Brigade was called at 0336 and the fire was under control at 0510. Fire crews from Poplar, Millwall, Bethnal Green, and Shadwell fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.