Flight disruption across the UK and Europe is set to continue after a suspected cyber-attack targeted automatic check-in and boarding software.
The technical issue resulted in London's Heathrow and Brussels airport 14 flights being cancelled at Brussels Airport on Saturday, and several more being delayed at London Heathrow, Berlin, and Dublin.
In a statement on Monday morning, software provider Collins Aerospace said it was in the final stages of completing necessary software updates.
Brussels Airport said the "service provider is actively working on the issue" but it was still "unclear" when the issue would be resolved.
They have asked airlines to cancel nearly 140 of their 276 scheduled outbound flights for Monday, according to the AP news agency.
Heathrow said on Sunday that efforts to resolve the issue were ongoing, and apologised to customers who had faced delayed travel.
It stressed "the vast majority of flights have continued to operate" and urged passengers to check their flight status before travelling to the airport.