Four prison officers were injured in a riot involving more than 30 inmates at a young offenders' institution.
A wing at Stoke Heath, near Market Drayton, Shropshire, was badly damaged during the disturbance, which went on for nine hours on Sunday evening.
It began when 33 inmates on 'A' wing refused to return to their cells. The national control and restraint team later moved in with riot gear.
A dozen inmates had to be sent to other jails because of damage to the cells.
One of the officers suffered a broken nose in the disturbance at the centre.
None of the young offenders were injured in the incident, which was brought under control in the early hours of Sunday.
At one point in-house staff withdrew and, after mediation failed, members of the national control and restraint team went in.
The wing houses 70 teenagers, aged 15 to 18, and the site has about 650 young offenders in total.
In a statement, the Prison Service said: "At 5pm 33 juvenile prisoners on Stoke Heath 'A' wing refused to return to their cells.
"Considerable damage was caused to the common areas of the wing.
"Specially-trained control and restraint officers and police officers were sent to the prison and the incident was resolved at 2.15am.
"The police will now be conducting an investigation.
"Seven (prisoners) are being held in the care and separation unit."
The chair of Stoke Heath's independent monitoring board, Jackie Whittle, said it was the first incident of its kind for many years.
She added: "Everything is smashed in the communal area and it's flooded as well.
"I think it started with a fight and became what we'd call concerted indiscipline.
"The officers were attacked by about 33 boys. 'A' wing is probably uninhabitable and I think the wing will have to be emptied.
"They were negotiating for a quiet outcome but eventually the national team went in at about [2330 BST]. I think some officers were hurt in the initial fight."