Image caption The last time doctors took industrial action was in 1975

Thousands of doctors in Northern Ireland have been taking strike action in a UK-wide protest over pensions.

Hospitals have cancelled some non-urgent operations and GPs are only accepting emergencies.

However, the planned opening of a new hospital in Enniskillen has gone ahead.

It is the first strike by doctors in almost 40 years. In a ballot of 104,000 members of the British Medical Association, the majority voted for a strike.

They oppose government moves to increase pension contributions and the introduction of a later retirement age.

What it means for patients The NHS is advising patients who need help in an emergency to use the service as they normally would.

Accident and emergency units will remain open, while mothers in labour will be able to go to maternity departments.

Appointments for urgent tests, such as for cancer, should also continue.

Routine appointments and operations could be affected.

Hospitals should already have alerted some patients their care has been rearranged.

Appointments could be cancelled on the day as doctors do not have to tell their employers they are taking action.

GP surgeries will be open and take emergency appointments. Patients are being told to ring up for even seemingly run-of-the-mill ailments like colds.

Advanced GP appointments for things such as medicine reviews or follow-ups are likely to have been cancelled by doctors taking part.

Dentists are not involved and so services will run as normal.

Just over half of GPs in Northern Ireland took part in the 24-hour industrial action, which began at midnight.

The strike could not have fallen on a worse date for the new South West Acute Hospital as Thursday saw the planned move of about 120 patients from the old Erne Hospital to the new site.

A trust spokesperson told BBC Northern Ireland that BMA members would be participating as planned in the transfer of patients. This move has been 12 months in the planning.

The BBC has also found that some trusts including the Western Health Trust said that if patients had not been contacted already, they should presume their appointment is going ahead.

In the Northern Health Trust about 280 patients were affected. A number of theatre sessions and outpatient clinics have been cancelled and routine appointments might not take place.

A spokesperson said: "All patients affected have been contacted and will be given a rescheduled appointment at the earliest opportunity.

"There will be minimal disruption to mental health services. Patients who have a scheduled appointment on Thursday should attend unless we have advised them not to. Urgent services will not be affected nor will community services."

We have a very good pension scheme which others in the private sector find very attractive, and we could not justify doing what we feel is inappropriate and not helpful Dr George O'Neill, GP who boycotted strike action

The BMA stressed the strike would not impact on patients' safety.

Dr Paul Darragh from the union's Northern Ireland branch said: "We were driven to this.

"We had a fair pension scheme that we had negotiated with the government four years ago by which new entrants to our scheme would have a normal pension age of 65.

"We increased contributions. There were tiered contributions by which those who were highest paid would offset the contributions of those who were lowest paid. We also had an agreement by which, if there was any increased cost for those pensions, it would be met by us and not the tax payer.

"The government has walked away from those agreements and refuses to negotiate with us."

The strike will have a knock-on effect for patients whose outpatient appointments or scheduled operations will be postponed.

One west Belfast GP said he was boycotting the strike action because it would only be the patients who suffer.

Dr George O'Neill said: "The partnership decided that we are reasonably well-rewarded.

"We have a very good pension scheme which others in the private sector find very attractive, and we could not justify doing what we feel is inappropriate and not helpful.

"It would not end up getting us the support that we need if we are going to influence and change government policy."

Thousands of people have been affected, including children and the elderly.

Some non-urgent hospital outpatient appointments and non-urgent surgery, including cataract operations, were cancelled.

Routine GP appointments were cancelled.

However, while a majority of GPs are taking action, a few are not and arrangements varied from one surgery to another.

Everything that is deemed urgent or life threatening has not been affected by the strike. All new cancer referrals including all cancer surgery was due to go ahead, as were emergency procedures such as heart surgery. Doctors carried out maternity ward rounds, so that mothers and new babies could expect to see a consultant.

All accident and emergency departments across Northern Ireland remained open; as did out-of-hours surgeries.