A problem with its check-in system has seen British Airways cancel almost 100 flights from the UK's two busiest airports, Heathrow and Gatwick.
British Airways has cancelled almost 100 flights from the United Kingdom's two busiest airports after suffering IT problems with its check-in system.
Thousands of passengers were affected after the airline axed 81 flights due to operate to or from Heathrow and 10 at Gatwick, while delaying more than 200 other flights on Wednesday.
Images showed long queues of passengers at the London airports and error messages on the BA app as some services lagged more than five hours behind schedule.
The airline is using back-up and manual systems to try to cope with the problems.
A spokesman said: "We are very sorry to our customers for the disruption to their travel plans.
"We are working as quickly as possible to resolve a systems issue which has resulted in a number of cancellations and delays today.
"A number of flights continue to operate but we are advising customers to check ba.com for the latest flight information before coming to the airport."
The airline is offering short-haul passengers departing from Heathrow, Gatwick and London City the chance to re-book to another day between Thursday and next Tuesday.
On Wednesday, holidaymakers had faced a struggle even getting to Gatwick after the Gatwick Express train service from London Victoria was cancelled.
A fire on the tracks between Victoria and Clapham Junction saw all early-morning Southern and Gatwick Express trains cancelled.