A bedroom at the Adult Acute Mental Health Inpatient Unit at Canberra Hospital.

A bedroom at the Adult Acute Mental Health Inpatient Unit at Canberra Hospital. Photo: Graham Tidy

Nurses at Canberra's adult mental health unit are being violently attacked by patients as the unit struggles with staffing issues and an increasingly high demand for beds.

Distressed workers say there is a worsening problem in the unit, with a rising number of assaults on nurses reported in recent weeks.

The ACT Health Directorate confirmed on Tuesday that as many as five nurses were attacked in the past week.

One was sent to the Canberra Hospital's emergency department, reportedly with lacerations to the neck.

Another was punched in the face during a violent outburst.

Staff are calling for extra nurses on the $26 million 35-bed unit and a 24-hour wards person who can respond to calls for assistance.

"Tired", "worn out" and "fearful" is the mood of many staff, according to Katrina Bracher, the executive director of ACT Mental Health, Justice Health and Alcohol and Drug Services.

Ms Bracher said on Tuesday the directorate was taking the concerns "really seriously" and was meeting with staff and the Australian Nursing Federation to consider measures, including employing an additional clinical nurse manager for the ward.

ACT Health is also likely to agree to a nursing union request for a review of nursing numbers.

Ms Bracher confirmed staff and union reports that the number of assaults had risen, partly due to a higher caseload of high-needs patients and a lower than normal mix of staff trained to deal with aggression.

She said the unit was also experiencing extremely high demand and had been forced to open extra beds and bring in more nurses, to accommodate patients, as well as keeping some patients in the emergency department.

The unit opened just over a year ago and its 35 beds were full within five months.

The government plans to expand the unit to 40 beds.

Ms Bracher said the nurses involved in the recent incidents were fine.

"The caveat on that, though, is nobody likes to experience that in their workplace and as the executive director it really saddens me that staff have experienced that in their workplace," she said.

"Being tired, being worn out, being fearful of that happening again - that is the mood on the ward at the moment.''

The nursing union said worried staff were concerned that 24-hour wards people, who were able to respond to incidents, were only stationed at the main hospital, which was more than five minutes away.

But Ms Bracher said health officers were on duty all day and it was important that the unit's philosophy remained therapeutic and not custodial.

"That means talking to people, monitoring early signs of deterioration, giving medication if needed," she said.

But she said an early duress call system needed to be put in place after some "fine tuning".

Nursing federation ACT secretary Jenny Miragaya said "nurses should be able to go to work and do their work and come home unscathed".

A spokesman for Health Minister Katy Gallagher, who is away this week, said the minister was aware of the issue and was working with the directorate.