Despite the level of threat being reduced, passengers travelling via London can expect and should be prepared for delays.

In fact, the delays begin at the original port of embarkation, which in my case was Bangkok's Don Muang airport, where flights departing for London saw long queues of passengers waiting to be checked in.

Even though everyone was going through the scanning machines, they were still being physically searched by security staff.

Duty-free purchases were removed from their original bags and placed in transparent ones.

Items, including personal belongings, containing liquids were placed in a bag with a name tag for the owner to collect at the end of the journey.

But the fuss really began when the plane arrived at Heathrow. Those whose final destination is London are blessed as they do not have to go through further delays.

Those with connecting flights, however, be they domestic or international, continue to face long queues for further security checks.

Signs indicating that no liquids, toiletries or cosmetics are allowed can be seen everywhere, with security personnel checking whether passengers' carry-on bags comply with the rules.

Currently, each passenger is allowed only one piece of carry-on luggage equivalent to the size of a small laptop bag. The rule is being strictly enforced and those who do not comply are being asked check out at passport control before checking back in again, with their carry-on bags going into the aircraft hold.

A process that normally takes about 15 minutes took at least an hour, meaning some people missed their connecting flights if they weren't quick enough.

A large number of British Airways passengers in a supposed fast-track lane found themselves queuing up for only one scanning machine.

Belts, shoes, laptops and jackets are all scanned. Because of this, many passengers were delayed and consequently missed their flights.

Airline staff seem overwhelmed by the situation and are having to deal with angry passengers, many of whom are having to stay at the airport in the hope of catching the next available flight.

Seeing the "You Can Still Buy" sign put up at the duty-free shops shows that the shops must be suffering from the tightened security.

I missed my connecting flight and had to wait at the airport for a further two hours for the next available flight. However, my suffering didn't end at the final destination. Despite having two extra hours at the airport - and I suppose those who take care of luggage would understand what they should do - my luggage wasn't on my flight, meaning another two hours waiting at the airport.

I was supposed to reach my accommodation before 11am, but it was a little after 4pm when I finally arrived.

Oh well. Never mind. After all, these hassles and delays are for our own security and safety!

Sopaporn Kurz

The Nation

Heathrow, London