Firefighters have issued bonfire safety guidance after a fire on Hillview Avenue in Harrow.
Garden sheds in the rear gardens of three properties were destroyed by the blaze. There were no reports of any injuries.
The Brigade's fire investigators believe the fire was accidental and caused by a bonfire.
A London Fire Brigade spokesperson said: "We would urge people to consider if their bonfire is necessary and to take care if you’re burning waste at home.
“Always check your local authority’s advice on bonfires and follow our safety tips.
"Never use paraffin or petrol on your bonfire and make sure you build it far away from any buildings, sheds and fences and never leave it unattended.”
The Brigade was called at 1423 and the fire was under control by 1540. Fire crew from Stanmore, Wembley and Northolt fire stations were at the scene.
Bonfire safety tips