Explosions were heard near the Old Bailey on Wednesday morning before smoke poured out of buildings nearby.
There are reported to be power outages in the area and around 25 firefighters are on the scene.
Firefighters said they were responding to an incident at an electrical substation near the rear of the court.
Footage showed staff being evacuated from the court building shortly after the fire alarm went off at around 10.40am.
Series of explosions heard from building next to Old Bailey for about 10 minutes before smoke emerges. Many buildings seem to have suffered power cuts. pic.twitter.com/GPnCs9cWAJ
— David Brown (@DavidhBrown) February 7, 2024
Footage showed black, acrid smoke billowing out onto the street by the court, known formally as the Central Criminal Court.
The London Fire Brigade said in a statement: “Four fire engines and around 25 firefighters are responding to an incident involving an electrical substation on Warwick Lane, near the rear of the Old Bailey.
“Traffic in the area is likely to be impacted as we respond.”
The court is the UK’s most high-profile criminal court. All proceedings at the Old Bailey are currently postponed as firefighters respond to the scene.
Among those taking place on Wednesday is the ongoing trial of Mark Gordon and Constance Marten, who are charged with manslaughter, concealing the birth of a child, and perverting the course of justice.