Up to 75 firefighters have remained at the scene of a fire in a building in central London for most of the night.
Crews were called to the Immigration and Appeals Commission building, in Chancery Lane, near Holborn, on Wednesday afternoon.
A London Fire Brigade spokeswoman said most of the roof of the five-storey was alight and also at least 50% of the fourth floor.
No-one was trapped inside the building, which was being refurbished.
At least 130 people left the building and nearby buildings before crews arrived. Witnesses said the fire spread rapidly.
Fire crews have remained at the scene to make sure the blaze does not spread further.
A Tribunal Service spokesman said staff had been trying to contact people due at the office on Thursday to stop them from attending.
Chancery Lane is an historic area, with some parts dating back centuries.
The area is predominately occupied by the legal profession and consulting firms.