Media playback is unsupported on your device Media caption Industrial action 'may delay cancer diagnoses' says Belfast Trust

Patients in Northern Ireland are facing a week of disruption, with more than 10,000 outpatient appointments and surgeries cancelled in Belfast.

Some people referred by their GPs on suspicion of cancer could have their diagnosis delayed, the head of the Belfast Health Trust has said.

The trust apologised, blaming industrial action on pay and staffing.

But the trade union Unison said it had been asked to exempt cancer services from its action and had agreed to that.

Northern Ireland Secretary Julian Smith told BBC News NI he was "extremely concerned" about the challenges facing the health service.

He said: "The government is clear this is one of a number of the urgent problems that we need a restored executive to tackle and that is why we are so focused on getting Stormont back."

Full details of the cancellations and advice for patients can be found on the Health and Social Care Board website.

Belfast Health Trust chief executive Martin Dillon said outpatient cancellations meant people due to have cancer diagnostic tests this week had had their appointments postponed.

Image caption Martin Dillon said some people suspected of having cancer may have to wait for tests

Speaking on BBC Radio Ulster's The Nolan Show, Mr Dillon said: "There are some patients whose GPs may well have a suspicion of cancer - not yet confirmed.

"Some of those people will have been due to have tests this week that would have confirmed that one way or the other.

"Regrettably we've had to stand those appointments down.

"This could potentially lead to a delay in diagnosis and could potentially lead to a delay in treatment."

Mr Dillon confirmed that all patients who are having cancer treatment would have their treatment as planned this week.

'Put this right'

Unison union members are carrying out waves of four-hour strikes on Monday.

Patricia McKeown, Unison's regional secretary, said that in talks with the Belfast Health Trust last week union officials were asked to exempt cancer services from their industrial action.

"Unison agreed to this along with a range of other exemptions," she said.

"The trust did not indicate any intention to cancel cancer diagnostic treatment - if it had done so it would have been exempted.

"We ask the Belfast Trust to urgently engage with Unison's local representatives to explain why they have taken this action and to put it right."

Ms McKeown also argued that three of the trusts had announced they would cancel all elective surgery some weeks ago, before her union confirmed its members were taking industrial action.

Image caption Patricia McKeown said the situation was not of Unison's making

She said the industrial action would be "cumulative" and it would be "an escalation".

"Right across the whole system, Unison members are working to rule.

"They are coming in to do their contracted jobs, they are stopping giving the tens of thousands of free hours they give to the health service every week in order to cover for missing colleagues."

'Patient care will continue'

The Royal College of Nursing's Northern Ireland director Pat Cullen said her union's members were "absolutely devastated" by such widespread cancellations.

"We as yet have no idea why such significant appointments will be cancelled because our nurses will be there to care for their patients," she said.

Nurses planned to take industrial action on Tuesday but would continue to do all direct patient care, she added.

They will not do the tasks usually performed by porters or administrators.

Image caption Some outpatient appointments will still take place at the places listed above

"We have been describing what has been a perfect storm in terms of the levels of vacancies within the nursing workforce and that has fallen on deaf ears," she said.

"Nurses cannot continue to work in the environment they are working in."

The trust is asking patients not to phone to reschedule due to the large numbers of people affected.

The South Eastern Health Trust is also cancelling some services but on a smaller scale.

Last week the Royal College of Surgeons warned Northern Ireland's healthcare system was "at the point of collapse" after waiting times reached an all-time high.

Where are the cancellations?

In Belfast, the following hospitals will have all outpatient appointments, day case procedures and planned surgeries cancelled on Monday, Tuesday and Thursday:

Royal Victoria Hospital (including the children's hospital, maternity hospital and school of dentistry)

Belfast City Hospital

Mater Hospital

Musgrave Park Hospital

However, some outpatient appointments will go ahead at these places:

Health and wellbeing centres

Community facilities

Chemotherapy or radiotherapy at either the Bridgewater suite or cancer centre at Belfast City Hospital

Macular clinic at Fairview

Paediatric oncology at the children's hospital

On Wednesday, all outpatient services will run as normal. Planned surgeries and day case procedures will still be postponed.

Emergency services and day centres are not affected by the industrial action.

In the South Eastern Health Trust area, all routine outpatient appointments at the Ulster Hospital have been cancelled on Wednesday, with the exception of maternity and children's services.

On Friday, outpatient departments at Ulster Hospital, Lagan Valley Hospital, Downe Hospital, Ards Hospital and Bangor Hospital will be closed in the afternoon.

Image copyright Pacemaker Image caption Members of Unison - NI's largest health workers' union - started their industrial action last week

Health workers across Northern Ireland are staging industrial action in protest at pay and staffing levels which they claim are "unsafe".

On Monday night, the Unite trade union said its members had voted to strike on 18 December.

It said it has 4,000 members who work in the health service and they would join members of the Royal College of Nursing, Unison and NIPSA in strike action.

The Department of Health said the serious disruption to services was "extremely distressing".

It said its offer of an independent conciliation process on the dispute stands.

"As we have been saying for some time, we simply don't have the money or authority to resolve this impasse and we strongly believe that patients should not be the ones to suffer because of that," the department said.

"Like our trust colleagues we would still wish to apologise to everyone affected."

The Northern Health Trust told the BBC that at present none of its services are affected.

However, the trust said it was working with Unison, with industrial action due to take place on Friday.

Updates can be found on its website.