The Health Service Executive has defended the placing of some teenagers in an adult psychiatric unit in Waterford despite the fact that it is only supposed to be done in exceptional circumstances.

Four teenagers, the youngest 14 years old, were admitted to the Waterford Adult Mental Health Services in the past few days.

Waterford Regional Hospital has a 44-bed psychiatric unit catering only for adults and there is no dedicated residential unit anywhere in the southeast for teenagers suffering from severe psychiatric problems.

Over Sunday and Monday, four teenagers, two boys and two girls aged 14 to 17 from different counties, were admitted to the adult unit at Waterford Regional Hospital.

They were kept in separate rooms away from adults, with their own en-suite facilities.

It is understood that at one stage, due to staff shortages, there was one nurse looking after more than 30 patients.

A security guard at the hospital was employed to look after the 14-year-old on the ward for a time.

The Psychiatric Nurses Association said staff are doing their best but that the situation is totally unacceptable.

The PNA said there were at least two teenagers admitted to the adult psychiatric ward at any one time over the last six weeks and it claimed it is also happening in other parts of the country.

The Department of Health said it accepts what is happening is inappropriate, but such admissions are sometimes necessary for the safety and treatment of the child because there is no alternative.

The HSE said it has an eight-bed child and adolescent psychiatric in-patient unit at St Stephen's Hospital in Cork.

That is an interim facility to cover Cork, Kerry, Waterford, Carlow, Kilkenny, south Tipperary and Wexford.

Speaking on RTÉ's Morning Ireland, Anna Marie Lanigan, Assistant National Director of the HSE South, said a new unit in Cork will open in eight weeks and will provide more facilities.