Five fire engines and around 35 firefighters tackled a fire at an office block on Lower Thames Street in the City of London.
Part of a plant room on the ninth floor was damaged by fire. Four people left the building before the Brigade arrived. There were no reports of any injuries.
Station Commander Alec McNally, who was at the scene, said: “The fire affected electrics and produced a strong burning smell throughout the local area, which has now subsided.
“Crews worked quickly to contain the fire and thankfully, no one was hurt.”
The Brigade was called at 0646 and the fire was under control by 0856. Fire crews from Dowgate, Whitechapel, Dockhead, Shoreditch and Shadwell fire stations attended the scene.
The fire is believed to have been accidental, caused by a fault in an electrical distribution board.