Around two thirds of GP practices in Northern Ireland have been impacted by a global IT outage.

Practices which have been affected are being asked to revert to “established paper-based processes where necessary” and are operating on an emergency appointment basis only.

Airline Ryanair said it had been forced to cancel a small number of flights and there has been disruption to vehicle testing services in the Republic of Ireland.

The outage has hit industries across the world, leading to cancelled flights and problems in some healthcare, retail and banking settings.

Cybersecurity firm Crowdstrike said a defect in one of its software updates affecting Microsoft Windows PCs.

A spokesperson for the Department of Health in Northern Ireland said there were a number of impacts to healthcare.

The spokesperson added: “The impacts are continuing to be collated, assessed and responded to urgently, patient care remains the priority and all HSC organisations continue to deliver services to patients as best as possible while the IT issues are fixed.

The impacts currently include hospital services – for example booking patients into operating theatres, accessing staff rosters, capturing digital endoscopy images and operating radiotherapy “services as well as some primary care services”.

“Around two thirds of GP practices across Northern Ireland use an IT system that has been affected.

“This means that these practices are unable to access their clinical system to view and update patient records, and cannot generate routine patient prescriptions and test requests or see results of laboratory tests.

“The affected practices will be operating on an emergency appointment basis only until the IT issues are resolved.”

The spokesperson added: “Teams are being asked to temporarily invoke the plans they have in place for continuing business without some of their IT systems, including reverting to established paper-based processes where necessary.

“HSC technology teams are working intensively with third party vendors to rectify the issue by removing the impacted component and will continue bringing systems back to normal during the course of the day.”

Any patients requiring an urgent supply of their regular prescription medicines who are unable to get a prescription from their GP, are being asked to contact their local community pharmacist to obtain the medication.

Gerard Greene, chief executive of Community Pharmacy Northern Ireland, reassured patients that pharmacies are dispensing medicines as normal.

He said: “Northern Ireland’s computerised dispensing systems are not affected by the current global IT issue.”

In Ireland the Health Service Executive said it has not yet seen any impact on its systems.

In travel, Ryanair said online check-in is available again following earlier disruption.

A statement on social media said: “We’ve been forced to cancel a small number of flights today (19 July) due to this Global 3rd party IT outage.”

Dublin Airport said that its systems are operating normally but that it had deployed additional staff in the terminals to help airlines and passengers.

Belfast International Airport said passengers were being processed as normal.

A statement said: “The airport is part of a global aviation network that is still experiencing disruption so delays and cancellations can be expected.”

A social media post from Belfast City Airport said operations had not been directly affected, but there would be disruption across networks.

In Ireland, the Road Safety Authority (RSA) said it was experiencing some disruption to services.

There had been disruption to vehicle testing services on Friday, but the RSA said all NCT centres were operational again by the evening.

A spokesperson said: “Applications for learner permits and driving licences cannot currently be processed at some NDLS centres.

“Work is continuing to rectify this and the RSA will update customers as soon as possible as to appropriate next steps.”