A "technical issue" at British Airways has delayed flights, reportedly for thousands of passengers.
Travel journalist Simon Calder said on X: "British Airways IT system failure is causing delays of 1-2 hours on many BA flights this evening... As delays build up I fear there will be cancellations tonight/tomorrow."
In a statement, British Airways said flights were "currently operating, but are experiencing delays" and that its teams were working to "resolve a technical issue affecting some of our systems".
Earlier media reports suggested dozens of flights were grounded and that communications systems were affected.
One X user pictured people queueing on the tarmac in Verona, Italy. "What has happened to the nations airline? Not fit for purpose," they said.
Replying to another X user BA said: "Our website is down. We are doing all we can to return online as soon as possible.
"Hopefully not too long before the Captain has his load sheet. Thanks for your understanding. Have a good journey when it is safe for you to be airborne."
A spokesperson for Heathrow Airport said: "We are aware of a technical issue that British Airways are investigating, and we will be working with them to provide updates to passengers as soon as they are available. Heathrow systems are operating as normal."
In June many British Airways (BA) flights in Heathrow were delayed by several hours by a "technical fault" with baggage handling.
BA said there had been a "temporary technical fault" which had disrupted its baggage system at the airport and had apologised for the problems it caused.
In January "intermittent issues" with the airline's app and website meant customers could not access them.
BA's customer score for long-haul flights was the joint third lowest out of 17 carriers analysed by Which? in February.
(c) Sky News 2024: British Airways flights delayed after 'technical issue'