The global IT outage has caused disruption across the UK, including to healthcare, transport and banking.

GPs have been struggling to access their records systems, which include online bookings. Pharmacy services, such as access to prescriptions, have also been affected.

The disruption has led to long queues at UK airports and knocked some TV channels off air.

Cyber security firm Crowdstrike said the global IT problems were caused by a defect in a content update and were not due to a security incident or cyberattack.

"The issue has been identified, isolated and a fix has been deployed," said George Kurtz, CEO of Crowdstrike.

Cabinet Office Minister Pat McFadden said the global outage was not a security attack or a hostile act.

He said: "The cause appears to be a software error in an update ... a fix is being put in place."

"We're very conscious that people are still being inconvenienced because of this, not just here in the UK, but in many other countries too."

The outage has also affected travel infrastructure across the UK.

Long queues have been reported at airports. British Airways said some flights were "likely to experience disruption".

The UK's largest airport, Heathrow, said the outage was affecting "select systems".

Train services are still running, though National Rail has said there were "widespread IT issues across the entire network", potentially leading to short-notice cancellations.

The outage meant several retailers were unable to take card payments for part of the day.

Gail's, Morrisons, Ladbrokes, Jempson's, Waitrose and Booths were among the chains affected - though some have since said the issue has been fixed.