Eight fire engines and around 40 firefighters have been called to a fire in a block of flats on Tysoe Road in Enfield.
The Brigade believes that the fire started externally and got into the fabric of the building via air vents. The fire badly damaged flats on the ground, first and second floor.
Around 30 people evacuated the block and there were no injuries.
The Brigade was called at 1614 and the fire was under control by 2018. Crews from Enfield, Chingford, Woodford, Tottenham and surrounding fire stations are at the scene.
The cause of the fire is under investigation.