Media playback is unsupported on your device Media caption Health Minister Edwin Poots described the incident as a "one off"

A major incident was declared at Belfast's Royal Victoria Hospital on Wednesday due to a large backlog of patients at the A&E department.

The hospital said additional staff had to be called in and extra beds opened to relieve pressure on the unit.

At one stage, 42 people were waiting on trolleys and staff described the situation as "horrendous".

The Belfast Trust said the situation was brought under control just before midnight.

Northern Ireland's Health Minister Edwin Poots was booed by protesting staff during a visit to the hospital on Thursday afternoon.

The health union Unison had been holding a protest at the RVH.

Earlier Mr Poots said problems had developed because staff had been dealing with a "massive number of admissions" over the past few days.

He said health staff had turned around what was "a very bad situation" within three hours.

He described the situation at the Belfast's Royal Victoria Hospital as a "one-off" incident, where there had been an "unreasonable spike" in patients requiring treatment.

Image copyright PAcemaker Image caption The trust declared a major incident at the Royal Victoria Hospital in Belfast

The chair of the health committee, Sinn Féin's Maeve McLaughlin, has called for a "full report into why a major incident was declared in the Royal Victoria Hospital Accident and Emergency Ward on what should have been a routine evening".

She added: "Since the closure of the A&E department in the City hospital, the Royal has been working under undue stress and Wednesday's nights episode was I believe the point where the system collapsed.

"It is obvious that the minister's strategy on A&E is in meltdown and lives are being put at risk and he must act now to reassure the public that this major incident response will not become the norm every week."

At about 20:00 GMT, trolleys from the emergency department were backed up into the x-ray area.

As a result, some A&E patients were placed in the recovery area and fracture clinic. The day procedure unit was also re-opened.

Joe McCusker from Unison said the situation at the hospital "had been on the cards".

'Seven hours of sheer hell'

"We have a crisis in our A&E services. It's not just a Belfast Trust issue, it's a Northern Ireland wide issue."

Mr McCusker said the problems in Belfast A&Es had been highlighted in a report by the College of Emergency Medicine last November.

"My concern is what is being done about this by the health minister and Health and Social Care Board," he said.

Analysis For several hours on Wednesday night, Belfast's Royal Victoria Hospital was "at breaking point", some members of staff said. But what is worrying was that this was no major trauma. There had been no major car accident or fire; there was no flu epidemic or winter vomiting bug. All of this happened against a relatively quiet backdrop. So why? The lack of middle-grade doctors across the United Kingdom is partly to blame. There is a 50% shortage affecting emergency departments nationwide. Staff burn-out in A&E is another issue. In November 2012, almost all of the emergency medicine consultants in the Belfast Health Trust raised concerns about the safety of A&E. Another problem for emergency departments is the four-hour target for patient waiting times. There is tremendous pressure on staff and on individual health trusts to tick that four-hour box. Ultimately one question must be put to Health Minister Edwin Poots. Is the current policy on accident and emergency working in Northern Ireland? What led to the crisis?

Staff at the hospital told the BBC that if a major trauma had been brought into the hospital on Wednesday night, there was neither space nor staff to cope with it.

Eamonn Hughes was at the hospital as his brother, Patrick, needed emergency treatment.

He described the scene as "seven hours of sheer hell".

"It was like something you would see in third world countries," he said.

Ambulances diverted

"The staff were overworked. There were hundreds of people who were not being attended to.

"This is a normal Wednesday night. There are no major disasters thankfully or car crashes, so I dread to think what would happen if something abnormal happened."

Ambulances were diverted to the Ulster Hospital in Dundonald for several hours during the evening.

The hospital said some patients were transferred to other sites.

Janice Smyth from the Royal College of Nursing said the situation on Wednesday night was "quite horrendous" and "totally unacceptable".

"The pressure on that department has been building for the last few weeks," she told BBC Radio Ulster's Nolan Show.

"We are really concerned that the situation was allowed to develop to the point that we had to implement a major incident plan to deal with it.

Media playback is unsupported on your device Media caption Eamonn Hughes, whose brother was taken to the Royal Victoria Hospital, describes "seven hours of sheer hell" in the emergency department

"Nurses are really concerned that patients are not getting the care they need and they're certainly not getting it in a dignified manner."

She said many staff members did not leave the department until 03:00 GMT on Thursday.

Colm Donaghy, the chief executive of the Belfast Health Trust, paid tribute to the staff.

He added: "Whenever we are under that level of pressure it can seem that we're not coping, but, in fact, we did cope".

"Normally when we have hundreds of people attending our A&E, we would expect to admit something like 27-28% of those people," he said.

"In the last couple of days we have been admitting over 40% of the people who have been attending."

Major incident planning is a part of our ongoing planning. It was unusual, but not unique, to declare a major incident Colm Donaghy, Belfast Health Trust

He said that there had been 10% rise in the numbers of people with fractures compared to last year, and there were also more people with respiratory conditions attending the hospital.

"Major incident planning is a part of our ongoing planning," he said. "It was unusual, but not unique, to declare a major incident.

"The circumstances differ at different times. Last night, I felt we had so many very ill and very sick patients that the way to deal with that was to ensure that we mobilised all of our resources."

He said at least 10 very senior medical staff were brought into cope with the situation, and more than 24 nurses.

'Goodwill of staff'

Mr Donaghy said that had a major accident or similar incident happened on Thursday night, the trust would have been able to handle it.

The health minister told the BBC that "the backlog was dealt with" and added that Northern Ireland has "a safer service now than we had two years ago, five years ago, ten years ago".

Mr Poots said: "What may be perceived to be normal wasn't actually normal because there was a build up of a series of very ill people. So for example, on Monday over 100 people were admitted to the Royal Victoria Hospital. Again on Tuesday, there was 110 admitted to the RVH.

Alison Millar, from the Nipsa union, said: "The trust is relying on the goodwill of staff who are stressed, overworked and are working under extreme pressure.

"Staff's goodwill is being taken for granted. The trust and the (health) minister need to take corporate responsibility for the provision of A&E services both in the Belfast Trust and across Northern Ireland."

In November 2011, Belfast City Hospital's Accident and Emergency Unit closed its doors and the Royal became the main hub of emergency care in Belfast.