Four fire engines and around 25 firefighters responded to an incident involving an electrical substation on Warwick Lane, near the rear of the Old Bailey.
Firefighters worked with UK Power Networks to make the scene safe and bring the fire under control. The ground floor substation was partly damaged in the incident. Around 1500 people were evacuated from the Old Bailey and surrounding area, and there are no reports of any injuries.
The Brigade received the first of six calls reporting the incident at 1044, and crews had the fire under control by 1407. Firefighters from Dowgate, Soho and Dockhead Fire Station attended the scene.
The fire is believed to have been accidental, caused by an electrical fault.