Staff shortages at the Southern Health Trust has led to the suspension of some non-emergency surgery.
The Southern Trust has been forced to suspend non-emergency surgery due to staff shortages.
It is one of three, along with the Belfast and Western Trusts, which have been forced to postpone surgical procedures.
The news comes just days before Unison starts strike action across NI, including Craigavon Hospital, which has already been hit by high numbers attending the Emergency Department.
A Trust spokesperson said: "Our priority is to ensure that there are appropriate numbers of nurses with the appropriate level of skill in our theatres to keep our patients safe.
"The shortage of theatre nurses is having an impact on our theatres and regrettably we are not currently able to operate at full capacity.
"We have been left with no option but to temporarily suspend some surgical sessions. This reduction equates to the capacity of one theatre in Craigavon Area Hospital and a part reduction in capacity of a theatre in Daisy Hill Hospital. Emergency, red flag and urgent surgery is continuing as normal.
"We continue to do everything possible to recruit nursing staff for theatres.”
This week Craigavon Area Hospital’s medical director told UTV the emergency department just experienced one of its worst ever evenings.
Dr Maria O'Kane revealed the hospital had 255 people through its doors on Tuesday evening.
Eighty-three of them had to wait more than 12 hours.
“I think last night was one of the worst nights that we’ve had,” she said.
“Unfortunately, there has been very little respite this year in terms of the activity across the different seasons. This pressure is relentless, day on day.”
Dr O’Kane said it was always a concern that such pressure would lead to lives being put at risk, but said that medical staff would “work to the highest possible safety standards to try to avoid that”.