Three juvenile detainees have been transferred to the notorious Unit 18 facility at Casuarina Prison as a result of the mass riot at Banksia Hill Juvenile Detention Centre, the State Government has revealed.

Nearly 50 juveniles, some armed, took over Banksia Hill Detention Centre for more than 14 hours on Tuesday and Wednesday, setting fire to cells and the facility and climbing up on the roof in a tense stand-off.