Significant queues are building at Dublin Airport - following a systems outage affecting check-in and boarding for Aer Lingus.
The airline has issued a statement apologising to passengers, and saying work is underway to solve a systems failure as soon as possible.
The company's website is also down.
Aer Lingus reservation systems are down, causing long queues for check-in at Dublin Airport.
There are reports of thousands of passengers impacted, who have now started queuing for metres outside the terminal.
The Aer Lingus website remains inaccessible, with a temporary image saying it's undergoing a 'scheduled upgrade.'
The company says a technical problem with its Cloud-based reservation and operational systems is impacting check-in and boarding,
It's expecting delays and disruption to services, for several hours.
The company is apologising to passengers for the inconvenience, and says its working to solve its connection issues as soon as possible.