A Victorian youth justice centre will remain in lockdown overnight after detainees attacked staff, including one hospitalised for facial injuries.
The fracas broke out in the Latrobe unit in the Malmsbury Youth Justice Centre in regional Victoria on Sunday afternoon.
Police and paramedics were called to the facility in regional Victoria about 2.45pm.
However, the situation was never handed to police and remained under the control of the security and emergency services group of Corrections Victoria.
It is understood the brawl was started by two boys and involved about five detainees.
However, Corrections staff locked down all three secure units, which house about 45 youths, during the incident and it will remain that way overnight.
Windows were smashed and a camera damaged in the incident, a Justice and Regulation Department spokesman said.
"Anti-social or violent behaviour in the youth-justice system will not be tolerated, and will be referred to police to identify whether charges should be laid," he said in a statement.
Police say one staff member will be treated for a facial injury.
An Ambulance Victoria spokesman said a man in his 30s was taken to Bendigo Hospital in a stable condition and paramedics treated two others at the facility.
Responsibility for the youth justice system was moved from the Department of Health and Human Services to the Department of Justice and Regulation in April after repeated riots and a mass escape.
Malmsbury holds youths both sentenced and on remand.
Last week, the state government lost a third legal battle to hold a group of teens in the adult Barwon Prison after parts of the Parkville Youth Justice Centre were rendered uninhabitable because of riots.
The youths could now seek compensation, but Youth Affairs Minister Jenny Mikakos says she is "unapologetic" for the way the teens were treated.