Four fire engines and around 25 firefighters were called to a fire at a restaurant on Park Road in Hornsey.
Part of a ground floor restaurant, the flat roof of a rear extension and part of the extraction system were damaged by fire. There were no reports of any injuries.
Park Road was closed whilst firefighters worked to make the scene safe and we advised people to avoid the area.
The fire is believed to have been accidental and caused by a fire in a chip fryer which spread to the extraction system and the flat roof above.
A London Fire Brigade spokesperson said: "We'd like to remind restaurant and takeaway owners to ensure they don't have dirty ducting. If you don't clean the ducting in your extraction system regularly, you're at a greater risk of ducting fires.
"You should also make sure you keep the hob, cooker hood and extractor fan clean too – built up fat and grease can ignite and cause a fire."
The Brigade was called at 1049 and the fire was under control by 1249. Fire crews from Kentish Town, Hornsey and Tottenham fire stations attended the scene.