London Fire Bridgade sent 25 fire engines the six-storey office building in Holborn at 10.40pm last night after a fire broke out on the roof. Crews from Soho, Dowgate, Euston,Islington, Lambeth, Whitechapel, Paddington, Shoreditch, Shadwell and Old Kent Road fire stations attended. A large amount of the roof and part of the fifth, fourth and third floors remains alight.
About 28 people left the building before emergency services arrived on the scene.
City of London Police said a number of road closures are in place around Chancery Lane and urged people to avoid the area if possible.
The cause of the fire is not yet known.