Four fire engines and around 25 firefighters were called to a fire at a shop with a restaurant above on New London Street in The City.
Part of the ground floor shop was damaged by fire. There were no reports of any injuries.
A London Fire Brigade spokesperson said: “The fire was discovered by a member of the public who saw smoke coming from a door on the ground floor. There were no working smoke alarms inside the property.
“Smoke alarms give the earliest possible warning when a fire starts and we would urge everyone to make sure they have one fitted in every room where a fire can start and a heat alarm in the kitchen.”
The Brigade was called at 2059 and the fire was under control by 2147. Fire crews from Whitechapel, Dowgate, Dockhead and Shadwell fire stations attended the scene.
The fire is believed to have been accidental and caused by an electrical fault in an extractor fan.