Customers affected by the cancellations will be able to change travel plans free of charge.
Aer Lingus has cancelled all flights from Dublin Airport to the UK and Europe on Saturday (10 September) from 2pm onwards due to
IT issues.
The airline made the announcement via a statement on Saturday afternoon.
"Due to a major incident with a network provider, our cloud-based systems enabling check-in, boarding and our website are currently unavailable," Aer Lingus said.
"A UK network provider servicing the cloud-based system has experienced a major break in connectivity impacting both primary and secondary connectivity. At this time the provider has not been able to give Aer Lingus an estimate of the time when the break in connectivity will be restored.
"Unfortunately, this is causing severe disruption to Aer Lingus services today.
"Consequently, all flights originally scheduled to depart from Dublin Airport for European and United Kingdom destinations from 2Pm onwards today have had to be cancelled.
"As we are currently unable to communicate directly with customers, we are asking customers booked to travel on those flights not to come to Dublin Airport.
"We sincerely apologise to all customers impacted by today’s disruption and cancellations.
"Any customer impacted by today’s disruptions will be able to change their travel plans, free of charge either through our call centre or social media channels. We will advise customers when IT systems are restored and this change option is fully available to our customers.
"As soon as systems are restored our teams will work to re-accommodate those impacted as efficiently as possible, and share information regarding customers’ rights and the airlines’ obligations under Regulation (EC) 261/2004.
"We are working intensively with our system partners and their network partners to resolve the connection issues as soon as possible."
The delays led to major queues in Dublin Airport, with check-in and boarding affected for all passengers.
Dublin Airport has said that the delays will not affect any other flights on Saturday.
