Hundreds of passengers have been left stranded after a number of flights to and from Belfast International Airport were cancelled.
Some EasyJet services to and from Bristol, Gatwick and Faro have been cancelled.
Meanwhile, holiday flights with TUI between Belfast and Malaga, Kos and Dalaman have all been disrupted.
Some passengers in Kos have not yet left the Greek Island despite their flight being scheduled to leave for Northern Ireland on Saturday.
On Monday morning, the International Airport website said its 6.10am flight to Gatwick with EasyJet was cancelled with the 6.40am Dalaman departure with TUI being delayed until 7pm.
Stephen Givan and his two friends Gillian McBride and Pamela Millar told UTV that Gatwick Airport was 'chaos' with people like them whose flights had been cancelled.
The trio were in Windsor for a weekend away but were forced to spend an extra night in England after their plane back to Belfast International was cancelled.
WATCH: Stephen, Gillian and Pamela talk to UTV:
"It was just chaos," Stephen told UTV from their hotel room, saying that all three of them have had to book a day off work because of the disruption.
"We managed to change our flights, but there are people who have young children, elderly people and people who can't use technology," Gillian said.
"We're probably the fortunate ones. It's just not a good way to end a fantastic weekend," she added.
Chloe Johnston was due to travel from Gatwick back home to Northern Ireland on Sunday night with EasyJet.
"We were told it was cancelled. No explanation was given and there were no staff on scene to help with enquiries or moving people on to next flight," Chloe told UTV.
Chloe managed to get booked onto an early morning departure the next day but other passengers on her original flight said the next service they could find was on Monday evening.
" There was no staff at all on site to manage the disruption. There were lots of people very distressed in tears worried at what hotels to book as everything was selling out and not sure if they would get the money back," Chloe explained.
Rosaleen Gormley was also left stranded in England last night after her EasyJet flight back to Belfast from Bristol was cancelled.
"We managed to get another flight booked for this morning but the app crashed when everyone tried to book hotel," Rosaleen said.
Rosaleen said staff then told passengers they would have to leave the airport to go to their overnight hotel.
In a statement to UTV, TUI apologised to customers travelling from Kos to Belfast, saying the flight has been disrupted "due to operational issues".
"Everyone has been able to stay in their hotels and meals have been provided. We are in touch and will update them with revised travel plans as soon as we can. "We understand that delays are frustrating and we thank all impacted customers for their patience.
"Customers on this flight are entitled to compensation in line with regulations and have already been sent information on how to submit a claim," the statement added.
In response, an EasyJet spokesperson said:
"We did all possible to minimise the impact of the disruption for our customers and customers were able to transfer to an alternative flight free of charge, or receive a voucher or a refund.
"The quickest and easiest way for customers to book a hotel and transfer to an alternative easyJet flight is always via Manage Bookings or through the easyJet app, and we also had a number of dedicated staff at Belfast airport available to assist.
"Customers can also contact us by phone to discuss other rerouting options, in line with EU261, and we always aim to reroute customers within 24 hours.” "While this was outside of our control, we are very sorry for the inconvenience caused by the cancellations. The safety and wellbeing of our passengers and crew is our highest priority.”
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