Youth detention centre riot 'terrorism', says premier

Authorities have regained control at Perth's Banksia Hill Detention Centre after dozens of rioting juveniles allegedly burned buildings, threatened staff and tried to escape the troubled facility.

A furious premier Mark McGowan said the behaviour of the youths was "a form of terrorism" and activists should not make excuses for them.

The major disturbance started after a number of detainees breached their cells about 8.30pm on Tuesday and gained access to the grounds of the centre before climbing onto the roof.

Mr McGowan said they lit fires in several accommodation blocks and caused extensive damage to the facility, where about 90 youths are detained.

"Obviously, it's total and utterly unacceptable," he said on Wednesday.

"It's a form of terrorism they are engaged in and they are behaving in an appalling way, with no respect for anyone."

The premier said inmates escaped their accommodation after a detainee threatened a custodial officer with a brick.

He said the officer retreated to a safe place to escape and as she did a master key got lodged in a door.

"The detainee took the key and then unlocked a range of accommodation units and cells around Banksia Hill."

Mr McGowan said more than half of the centre's inmates left their units and cells once they were unlocked.

"The authorities then declared there was an emergency ... (and) scrambled various resources to try and contain the situation," he said.

This included the special operations group and firefighters who were supported by a large police contingent including a helicopter and dog unit.

"A range of (detainees) then tried to stop the fire trucks from getting access to put out fires," Mr McGowan said.

Others threw debris at staff and authorities from the roof and rammed a motorised buggy used in the centre into gates and doors. 

"Fortunately none of the staff were injured," he said.

"A range of them (also) started tying sheets together to try and climb the fences but fortunately the accommodation is secure and there was no prospect of them escaping."

Mr McGowan moved to silence critics of the centre "before people start making excuses".

"Before anyone starts to try and blame anyone else, the people who did it are responsible. Don't blame other people," he said.

"The reason they are in Banksia Hill ... is multiple and I mean multiple armed robberies, burglaries, rapes, some have killed people, stealing police cars and driving at police.

"They show no respect, no respect for anyone."

The premier said he would meet other members of his government, the Department of Justice and the police commissioner to discuss tougher punishment for juvenile offenders.

He also said some of the inmates would need to be moved to adult facilities because of the significant damage at Banksia Hill.

Banksia Hill is a juvenile facility for offenders aged 10 to 17.

In February a guard suffered a suspected fractured skull after being hit by objects allegedly thrown by detainees.