LONDON — British Airways was still grappling on Monday with the impact of a major technical failure over the weekend, which has led to hundreds of flights being canceled and affected around 75,000 passengers.

The airline said on Monday that it was running most flights as normal, but the disruption has resulted in tense scenes at London’s two biggest airports in particular. British Airways’s sister carriers, like Iberia in Spain, have also been hit with cancellations.

Alex Cruz, the chief executive of British Airways, apologized to customers and promised that a majority of passengers affected by the failure would reach their destinations by Monday. But that is unlikely to placate many passengers, as Monday is the end of a long holiday weekend.

What Happened?

A global computer failure that began on Saturday morning led to the canceling of all British Airways flights from its hubs at Heathrow and Gatwick airports in London.