Firefighters have issued a smoking safety reminder after a fire at a builders yard on Towpath Road in Edmonton.
A stack of around 30 railway sleepers and timber was damaged by the fire.
The Brigade's fire investigators believe the cause of the fire was the unsafe disposal of smoking materials.
A London Fire Brigade spokesperson said: "If you smoke, it is vitally important you ensure your cigarette is disposed of carefully by stubbing it out, preferably in an ash tray.
"If you smoke before bed, make sure your cigarette is fully out and never leave your lit cigarette unattended. As we’ve seen here, carelessly discarded cigarettes can easily start fires."
The Brigade was called at 0435 and the fire was under control by 0542. Fire crews from Chingford, Walthamstow and Edmonton fire stations attended the scene.