Thousands of travellers have been stranded after British Airways' online check-in system crashed due to an IT glitch.
The airline apologised to customers for the disruption and said its technical team was working to resolve the problem.
"We are experiencing some systems problems this morning which are affecting check-in and flight departures," it said.
"This is affecting other systems as well."
Just over a year ago, BA was forced to cancel flights at Heathrow, due to problems with a supplier's IT system.

British PM Starmer to send four Typhoon jets to Qatar
Bombing of Tehran intensifies as war enters day six
Azerbaijan vows to respond after four injured by Iranian drones
72 killed in Israeli attacks on Lebanon as it warns residents to leave south
