Aer Lingus has resumed flights from Irish airports to London Heathrow following this morning's anti-terror operation in Britain.
The airline says it hopes to have its schedule back to normal as soon as possible.
More than 30 flights between Ireland and Britain were disrupted today as a result of the security alert in the UK and thousands of passengers had their travel plans disrupted.
Many flights to the UK were cancelled while hand baggage restrictions were introduced on some transatlantic flights.
Flights to Heathrow from Dublin, Cork and Shannon airports were cancelled as well as most flights from Ireland to Stansted following this morning's anti-terror operation in Britain.
Transatlantic passengers are being advised of certain hand baggage restrictions, with Aer Lingus banning hand luggage for passengers who are flying to Britain and then getting connecting flights onto another destination.
Mobile phones and keys are included in the ban.
All transatlantic passengers are being told they cannot bring any liquids onto planes, which means they cannot buy duty-free drinks and perfume.
Cullen: No increased security risk at Irish airports
The Minister for Transport, Martin Cullen, said there was no increased security risk at Irish airports, and that his department is continuing to monitor the situation closely.
Minister for Agriculture and Food, Mary Coughlan, has said Ireland is not facing a security threat.
She was speaking following a meeting of the National Security Committee, which briefed the Government and the Taoiseach on security issues.
Aer Lingus has set up a telephone service for passengers affected by this morning's disruption. The number is 0818 365 044.
Ryanair is advising all passengers who have booked flights to the UK or other destinations that they may change to an alternative flight free of charge, subject to availability.
Flight delays of one to two hours were reported at Belfast City, Belfast International and Derry City airports.
Flight Information & Contact Details:
British Airports Authority: www.baa.co.uk
Heathrow Airport: www.heathrowairport.com Tel: +44 (0)870 000 0123
Gatwick Airport: www.gatwickairport.com
Tel: +44 (0)870 000 2468
Stansted Airport: www.stanstedairport.com Tel: +44 (0)870 000 0303
Manchester Airport: www.manchesterairport.co.uk Tel: +44 (0)161 489 3000
Belfast International Airport
www.belfastairport.com Tel: +44 (0)28 9448 4848
George Best Belfast City Airport
www.belfastcityairport.com Tel: +44 (0)28 9093 9093
Derry City Airport
www.cityofderryairport.com Tel: +44 (0)28 7181 0784
Dublin Airport: Dublin Airport is warning of long delays. www.dublin-airport.com
Aer Lingus Emergency Number: Tel: 0818 365 044
Cork Airport: www.corkairport.com Tel: 021 4313131
Shannon Airport: www.shannonairport.com Tel: 061 712000
Ireland West Airport, Knock: www.knockairport.com Tel: 094 9368100