Van Uk, 19, James Nunn, 18, Grayson Toilolo, 18, and Joshua Keuth, 18, were held on remand at the Grevillia Unit at Barwon Prison over the weekend while a magistrate considered whether to permanently move them to the adult system.

Their matter was heard before the Bendigo Magistrates’ Court on Monday.

The court heard the four inmates, along with two minors, allegedly covered CCTV cameras before jumping over a duty point counter and stealing the metal legs from tables at 1.15pm on Thursday.

They allegedly smashed a door to the courtyard and were seen to “go from unit to unit”. A total of 30 windows, two air conditioning units, a washing machine, smoke detectors and 12 cameras were smashed or extensively damaged.

The Malmsbury response team could not stop the inmates, so the Victoria Police Critical Incident Response Team was called in.

The only injury from the incident was a scratched finger.

The inmates were each charged with one count of criminal damage.

Magistrate Sarah Leighfield had to consider each inmate’s alleged role in the incident, their age, prior convictions, remaining length of their sentence and whether further management layers could be put in place to prevent further incidents.

The court heard three of them – minus Nunn – were involved in a gang in the Malmsbury centre, and each had served time in isolation under the individual behaviour management plans. The plan lasts for a maximum of 72 hours, with a further assessment afterwards.

Toilolo had met with the parole board to discuss his behaviour three days before the incident. Toilolo and Uk allegedly assaulted staff members in the past.

Kouth and Nunn have allegedly assaulted “vulnerable clients” in the centre.

Malmsbury Youth Justice Centre operations manager Rick Madigan told the court none of the boys would pass a “suitability assessment” to return to the centre.

He said they had exhausted each layer of management, and isolation was no longer an effective tool.

“I believe isolation isn’t a long-term solution for the clients, it’s a short-term solution to get them back on track,” Mr Madigan said.

“I think the adult system has more access to behaviour management units to separate these four clients.”

Mr Madigan said “systemic problems” in the youth justice system had contributed to the rise in violent incidents and rioting.

The four spent the weekend in 23-hour lockdown in the Grevillia Unit at Barwon Prison, which the state government earlier gazetted to allow for youth inmates.

There were no reported problems from the weekend.

Prosecutor Senior Constable Cherree Blair said each client was at the highest level of management already, and they “cannot be properly controlled”.

Chris Wareham, representing Toilolo, said the “emergency situation is passing”, and his client is “very anxious” about moving into adult custody.

Magistrate Leighfield said transferring the inmates to adult custody was a “last resort”, but all other options had been exhausted.

The four were remanded in custody to appear in the Bendigo Magistrates’ Court on February 9.