The incidents come as the Government struggles to adequately staff the facility, with private security guards commissioned to fill the gaps for at least the past four months.

The three violent assaults happened last Tuesday, Wednesday and Friday.

A spokesman for Minister for Children Joy Burch confirmed several detainees attacked a staff member without warning or provocation in the most serious incident.

The Canberra Times understands three detainees were involved in the attack.

The spokesman said, ''The youth detention officer managed the incident well, eventually restraining the main aggressor whilst assistance arrived.''

It was unclear if the staff member was injured.

Staff in the other two attacks completed their shift and returned to duties. It is believed a staff member was punched in the head in one of the incidents.

''The department treats any assault on a staff member seriously,'' the spokesman said. He said staff were debriefed after the assaults, with ongoing monitoring and assessment.

For more on this story, including detials of previous attacks on staff at the centre, see the print edition of today's Canberra Times.