Four fire engines and around 20 firefighters and officers were called to a fire at a car breakers yard in Upton Lane, Forest Gate.
Part of the ground floor and first floor of a two storey unit was damaged by fire.
The Brigade was called at 0056 and the fire was under control at 0208. Fire crews from Stratford, Leytonstone, Plaistow and East Ham fire stations attended the scene.
The cause of the fire is believed to be accidental.