A huge blaze has broken out at a derelict building on the old Broadmoor Hospital site.
Crews from Royal Berkshire Fire and Rescue service are in attendance at the site.
Emergency services have confirmed the current hospital site is not impacted.
Nearby residents are being urged to keep their windows closed while crews deal with the blaze.
Fire at Broadmoor HospitalX/@Harryaspinall4A spokesperson from Royal Berkshire Fire and Rescue Service said: "We are attending a fire at a derelict building on the old Broadmoor Hospital site.
"The current hospital site is not affected.
"Please stay clear of the area but if you are nearby, please keep windows and doors closed."
A Thames Valley Police spokesman added: "At this stage there is no impact to the wider road network."
LATEST DEVELOPMENTS
Broadmoor holds the man who tried to kidnap Princess Anne in 1974, Ian Ball, and one of Lee Rigby's killers, Michael Adebowale
PA
Today, Broadmoor holds the man who tried to kidnap Princess Anne in 1974, Ian Ball, and one of Lee Rigby's killers, Michael Adebowale.
Broadmoor Hospital has housed a number of sadistic killers since it opened its doors in 1863, including Yorkshire Ripper Peter Sutcliffe, gangster Ronnie Kray and rapist Robert Napper.
New Broadmoor Hospital, which sits next to the older buildings, opened in 2019, after it was decided the Victorian structures were no longer fit for purpose.
The institution for the criminally insane was built after the creation of the Criminal Lunatics Act 1860, also called the Broadmoor Act.
The Broadmoor criminal lunatic asylum was opened in 1863 holding 95 female patients, with a block for male patients being added a year later.
It is not known if there have been any injuries in the fire yet.