Over 1000 airline passengers were delayed after air traffic control shut down overnight at Dublin Airport.
The disruption was sparked by an ongoing row between air traffic controllers and the Irish Aviation Authority (IAA) over staffing levels.
Air traffic services were withdrawn at Dublin Airport between 11.30pm last night and 6.30am this morning.Staffing levels are now back to normal and there are no further delays expected.
An IAA spokeswoman said Aer Lingus and Ryanair passengers were affected. The IAA said the latest disruption was because they could not get anyone to cover for an air traffic controller who called in sick.
"The Irish Aviation Authority regrets the inconvenience to the travelling public and to airlines," added the spokeswoman.
The industrial action over roster changes and overtime has already seen disruption at both Cork and Shannon airports.
Further talks are scheduled to take place at the Labour Relations Commission next Tuesday between the IAA and the Impact union, which represents the air traffic controllers.