British Airways flights grounded after global IT outage

British Airways aircraft at London's Heathrow Airport. (File photo: AFP/Carl De Souza)

"We have experienced a major IT system failure that is causing very severe disruption to our flight operations worldwide," BA said in a statement.

It had earlier cancelled flights before 6pm UK time (1700 GMT) but later extended the cancellations to the rest of Saturday.

The airline said most long-haul flights due to come to the airports on Sunday would arrive as expected but there would be further delays and disruption to its services.

BA added that it has found "no evidence that it's a cyberattack," with Britain still recovering from a ransomware attack that crippled key infrastructure earlier this month.

Passengers reported massive hold-ups at airports and planes being held on runways.

The problems, which passengers said were affecting flights across the country, came on a particularly busy weekend in Britain with a public holiday on Monday and many children starting their school half-term breaks.

"We apologise to customers who are facing some delays following an IT outage this morning," a BA spokeswoman said. "We are working to resolve the problem as quickly as possible."

Passengers on social media reported long delays and flights by the IAG-owned airline being held on runways, at the start of a long holiday weekend in Britain.

Passenger Roshni Burt, who was flying from Heathrow to Bahrain with her young son, said there was no news about when her flight would depart.

"When we left the check-in area there were angry people, people getting frustrated that their flights were coming up or near to departure, people getting turned away ... with BA staff basically saying 'if you've not checked in online, you've missed your flight'," she told Sky News.

Delays were also reported in Rome, Prague, Milan, Stockholm and Malaga, with the airline unable to say when flights would resume during the busy bank holiday weekend.

Alma Saffari told the BBC that her flight from Marseille to London had been grounded.

"When we finally boarded the captain came out and told us their computer systems were down worldwide," she said.

"Eventually after sitting on the tarmac for one and a half hours we disembarked the plane.

"Now we are sitting in the departure area outside the gate."

BA is the latest airline to be hit by computer problems. Last month Lufthansa and Air France suffered a global system outage which prevented them from boarding passengers.