Broadly, passengers are not being allowed to take on any hand luggage except essential items in see-through carrier bags, and are advised to expect delays.

Passengers are advised to contact their airline with any queries.

The information is subject to change.

Links to airport websites have been included, although readers may experience difficulties accessing some of them because of high demand (and please note the BBC is not responsible for the content of external websites).

Passengers are being advised to check in at least two hours earlier. No hand luggage is allowed to be taken on, with only the barest essentials in transparent plastic bags.

Belfast International Airport security director Robin Long said delays would be inevitable.

"Unusually, we are searching absolutely everybody so that is having a massive impact," he said.

Easyjet flights from the airport to Amsterdam, London Gatwick, Liverpool, Luton and Newcastle have been cancelled, as have the airline's incoming flights from Luton, Gatwick, Liverpool, Amsterdam and Newcastle. All Easyjet flights arriving and leaving from Luton, Gatwick and Stansted airports have also been cancelled.

All BMI baby flights to and from the airport have been cancelled. These include flights from Manchester, Nottingham, Cardiff and Birmingham.

The airport says all flights are experiencing delays.

Flights to and from Heathrow and Stansted have been cancelled.

The airport has asked passengers to arrive as early as possible.

The airport says check-in for all flights will close an hour before departure.

Long delays are being experienced at the airport.

Aer Lingus has advised passengers to cancel all non-essential travel to UK airports. However, it has now resumed flights from Irish airports to London Heathrow.

The airline says it hopes to have its schedule back to normal as soon as possible.

Ryanair said passengers with flights booked to the UK may change to an alternative flight free of charge, subject to availability.

Currently, travellers must place all personal property in their hold luggage with only the following allowed on board aircraft as hand luggage:

Pocket-sized wallets and purses, plus contents Passports and travel tickets Prescription medicines, not in liquid form unless can be verified as authentic Essential medical items such as diabetic kit Glasses and sunglasses, no cases Contact lens holders, no bottles of solution

Baby food and milk for those with infants - contents of each bottle must be tasted by accompanying passenger Essential sanitary items for infants Female sanitary items, unboxed Tissues, unboxed, or handkerchiefs Keys, but no electric key fobs