Four fire engines and around 25 firefighters were called to reports of smoke in Potters Fields in Southwark.
Firefighters investigated and traced the smoke to a small rubbish fire adjacent to an external wall.
The Brigade was called at 0956 and the incident was over for firefighters at 1057. Fire crews from Dockhead, Whitechapel, Dowgate and Old Kent Road fire stations attended the scene.
The cause of the fire was accidental and due to the unsafe disposal of smoking materials.