The Law Society HQ in Chancery Lane, Holborn, Central London

The Law Society of England and Wales' Chancery Lane headquarters was evacuated on Saturday night after a fire broke out, requiring more than 100 firefighters and 25 fire engines to put it out.

Though the London Fire Brigade (LFB) confirmed that there were no injuries, it described the blaze as "very complex", owing to the building's age and layout.

The LFB tweeted that the fire had been brought under control after some hours, but crews were to "remain on scene throughout the day damping down and carrying out salvage work to minimise damage to the building".

The Law Society confirmed in a statement that the fire had affected its premises on 113 and 114 Chancery Lane in Central London.

The organisation's chief executive Paul Tennant said: "First of all I wanted to express my gratitude to the fire service and my relief that nobody has been hurt. I also want to express my sympathy to the residents in the Chancery Lane area whom I understand may have had to evacuate their homes.

"It is too early to comment on the cause of the fire or the extent of the damage but clearly we are extremely upset that this has happened to this wonderful and historic building.

Fire engines were called out on Saturday night after a fire broke out on the building's roof. Credit: London Fire Brigade

"When the fire alarm sounded on Saturday night an event had been taking place. An evacuation ensued and I'd like to praise our on-site staff and others for their calm response. We will release more information as it emerges in due course."

Eduardo Reyes, features editor at the Law Society Gazette – which is based in the same premises as its publisher – tweeted that the magazine's offices were "among the floors gutted", but indicated that the building's historic library remains intact.

The Law Society is the professional body for solicitors, representing around 180,000 lawyers across England and Wales.

A Grade II listed building, the Chancery Lane HQ first opened its doors in 1832, according to a document, after the Society waited over 75 years to acquire the site.