More than a dozen prison staff were injured after a riot broke out at Feltham young offenders' institute.
The prison, in south west London, is home to male offenders aged between 15 and 21 years old.
The violence unfolded around lunchtime on December 27 and was over “within 25 minutes”, according to the Ministry of Justice.
None of the 14 workers were seriously injured, a spokesman for the MOJ added.
It is not known how many inmates took part in the violence.
A Prison Service spokesman said: “An incident at Feltham Young Offender Institute was quickly resolved by our brave and diligent prison officers.
“We will never tolerate violence against our staff and will punish those involved.”
Feltham is home to around 100 boys and young men aged between 15 and 21.
An inspection report published in June identified soaring levels of violence and self-harm, high use of staff force, poor care and long periods of lock-up in cells in Feltham A, which holds offenders aged 15-18.
It prompted the Government to halt placements at the unit.
The MoJ said there had been a sustained reduction in levels of assaults on staff, self-harm and use of force between the start of May and the end of August, but there are no plans to return the establishment to full capacity.
