Twenty-one people have been charged after a riot at a juvenile justice centre on the NSW Central Coast which lasted more than 20 hours.
The riot broke out at Frank Baxter Juvenile Justice Centre at Kariong on Sunday night.
It's alleged several inmates assaulted each other and then climbed onto the roof of the complex.
Seven people were injured and six were taken to hospital, including an 18-year-old who was initially in a critical condition with stab wounds and facial injuries.
He's now in a serious but stable condition at Gosford Hospital while a 17-year-old and a 20-year-old remain stable.
Nine detainees surrendered on Monday before riot squad officers moved on to the roof about 5.30pm - 21 hours after the riot started - and the remaining 11 detainees surrendered peacefully, NSW Police said.
Five adults and 16 youths have been charged with rioting.
One of the adults faced Gosford Local Court on Monday with his matter next due for mention on August 16.
The remaining four had their matters mentioned in the same court on Tuesday with all due back on August 9.
The 16 youths were expected to appear in Woy Woy Children's Court on Tuesday.
NSW Communities Minister Gareth Ward said the incident was unacceptable and ordered an independent review.
It will be conducted by former assistant police commissioner Lee Shearer and is in addition to plans already in place to establish a unit at the complex to manage high-risk offenders.
"This inquiry will get to the bottom of what happened at Frank Baxter," Mr Ward said in a statement on Monday.
Public Service Association general secretary Stewart Little alleged the group targeted sex offenders within the complex and described the riot as "nothing short of horrific".
He called for a judicial inquiry into the juvenile system, noting it wasn't the first riot at the centre.
Three units at the juvenile justice centre were damaged in the riots and remain part of a police crime scene, a spokesman for the Department of Communities and Justice told AAP.
The loss of the units has meant some of the centre's young inmates have been moved to other complexes.
Australian Associated Press
