Disgruntled prison officers are blaming two incidents this week when inmates armed with weapons barricaded themselves inside rooms and destroyed property on a soft punishment regime at Perth's juvenile detention centre.
The Department of Corrective Services' special operations group were brought in and used flash bombs and pepper spray on four males aged 17 and 18 who barricaded themselves in a wing of the Banksia Hill centre on Thursday.
The detainees smashed windows and pulled doors off cupboards, the fridge and oven and the centre was in lockdown from 12.55pm to 2.30pm, according to the CPSU/CSA union, causing up to $150,000 damage.
A similar incident occurred on Monday when three teenagers barricaded themselves inside a unit and smashed a television and furniture.
AAP has been told there has been an increasing number of incidents involving property damage, assaults on staff and assaults between detainees in the last four months.
Staff were also worried that both of this week's incidents were planned and inmates had makeshift weapons.
Some staff are blaming "a lack of consequences" for detainees with punishments that don't fit bad behaviour.
"There is a good chance the four guys involved in the riots yesterday would get their TVs taken away from them for 24 hours, that's it," a source told AAP.
"Detainees know that and are playing up on it."
The union will complain to the department that it had gone too far in its restructure since a 2013 riot at Banksia Hill, including a focus on creating less of a prison environment with more counselling, education and scaled-down punishments.
It will also raise concerns about 16 per cent of Banksia Hill's 140 detainees being aged over 18, including a 22-year-old there last month.
The Labor Opposition corrective services spokesman Paul Papalia said he was told two younger detainees had also been held against their will during the incident.
"I'm very disturbed as it indicates young people in there are at risk from older detainees, which is not acceptable as the government has a duty of care to these often very young people ... juveniles as young as 10 are in this place," he told reporters.
He blamed the WA government for shutting WA's only other juvenile facility in late 2012, the Rangeview Remand Centre, combining remand prisoners with sentenced prisoners.
"In 2012 the government, against the advice of the people who work in this facility and against the advice of the opposition, chose to shut the juvenile remand centre and cram all of the juveniles into one facility," corrective services spokesman Paul Papalia told reporters.
Within months there was the riot at Banksia Hill involving 60 inmates
The Inspector of Custodial Services Neil Morgan criticised Corrective Services at the time.
Corrective Services commissioner James McMahon said there had been impressive cultural change at Banksia Hill since 2013 and the staff supported the focus on rehabilitation.
He said the fact that this week's incidents were resolved without injuries meant it was handled properly and the reasons for the disturbances were being investigated.
