Riot crews had to be called in to control prisoners when trouble flared at the Aylesbury Young Offenders’ Institute.
Eight prisoners were involved in a riot in A Wing, with a stand-off between inmates and officers lasting more than six-and-a-half hours.
Prisoners began to cause trouble at 10.15am on Saturday.
Staff had to evacuate the wing and riot crews were called in to handle what was described as a ‘siege’.
A number of emergency service vehicles were seen outside the Bierton Road institute while the incident was taking place.
The incident was resolved at around 4.55pm.
One prisoner received treatment for minor injuries but no staff were injured.
Prisoners have been moved out of the wing while broken windows and damaged floors are repaired.
Inmates are expected return to the area by the end of the week.
Police are investigating what happened.