London Fire Brigade responded to the fire at around 2.45pm this afternoon (July 12) after receiving 70 calls.
A large fire has broken out at a shop that has two floors of flats above, causing black smoke to billow into the sky.
A loft conversion and a row of garages behind the building are on fire.
Crews from Stanmore, Mill Hill, Willesden and West Hampstead fire stations are at the scene in 15 fire engines.
A LFB spokesperson said that the cause of the fire is not known at this stage.
Station Commander Stephen McGhie said: “We are working tirelessly to prevent the fire from spreading to further properties.
“Residents in the area are advised to keep their doors and windows shut due to the smoke. We also advise people avoid the area as the road is closed in both directions.”
Church Lane has been blocked off both ways at Elthorne Road by firefighters. A detour in operation for bus route 83 and 302.