Specialist officers had to be called in after about 40 prisoners began a riot and set alight an open prison, according to the Ministry of Justice.
The prisoners at HMP Ford near Arundel, West Sussex, began smashing windows, activating fire alarms before setting the building alight.
Staff were forced to retreat from the section and police and specialist prison officers were called in.
A Ministry of Justice spokesman said no injuries to prisoners or staff had been reported.
He said: “At around 12am about 40 prisoners began smashing windows and setting off fire alarms at the establishment and set one building alight.
“Prison staff were forced to retreat and police and the fire brigade have been called.
“Specialist teams of prison officers have been called in to deal with the incident.
“We have no reports of any injuries to staff or prisoners at this stage.”
A Prison Service spokesman later confirmed that fires had been started in a small number of buildings at the site.