Almost two dozen flights to and from Ireland to Spain and France have been cancelled because of a strike by French air traffic controllers.
The 36-hour industrial action which began yesterday evening will continue until tomorrow morning.
The French Civil Aviation Authority has said flight delays and last-minute cancellations cannot be ruled out.
Intending passengers are being asked to check their airline websites for updates.
Twenty-three Ryanair and Aer Lingus flights to and from France and Spain have been cancelled today.
Ryanair has said that so far this year, strikes staged by air traffic controllers in France have led to the cancellation of 4,000 flights.
Last week, the airline handed in a petition with over a million signatures to the European Commission, demanding that it take action to protect overflights across the union during air traffic control strikes to keep skies open.

Research Highlights High Level Of Energy Drink Consumption Among Young People
Taoiseach And Ministers To Travel To New York For UN General Assembly
Google Fined €403M Over Handling Of Location Data
Kildare TD Says He Won't Be Intimidated Amid Widespread Political Harassment Fears
Four People Killed In Separate Road Crashes Across Ireland
Cabinet To Discuss School Meals Programme Amid Criticism Of Nutritonal Standards
Two People Killed In Separate Road Crashes Within 40 Minutes
Two Teenagers Arrested For Wrong-Way Driving Of A Stolen Car And Ramming Garda Vehicle