Airport security is being stepped up around the world in response to the Christmas Day attempt to bring down an airliner flying to the US city of Detroit.
Here, BBC News explains the various security measures being deployed in airports across the world. The most advanced air terminals will have all the latest measures, others will have fewer.
Click on the blue boxes for details.
- Strict regulations exist about what can be carried in hand luggage and checked-in baggage:
- - Sharp objects must be checked-in.
- - Maximum size for hand luggage is typically 56cm x 45cm x 25cm.
- - Small amounts of liquids are allowed if in a transparent bag.
- - Containers larger than 100ml are not permitted.
Checked baggage passes through large-scale x-ray machines and may be checked by sniffer dogs. All bags are kept completely separate from passenger areas in the terminal.
Hand luggage check
Hand baggage is scanned for illegal items with an X-ray machine. Sniffer dogs and chemical hand swabs may be used to detect explosives. Explosives detector machines are currently being developed and may well be introduced in the future. Detectors are also in development that could identify different types of liquids.
All passengers must pass through a metal detector and or body image scanner. Body image scanners, that reveal items beneath clothing or on the body, are being introduced in a number of countries following the 2009 Christmas Day attempted attack.
Names of all passengers flying to the US must be submitted to US officials for cross-referencing against a database of "high-risk" terror suspects. New biometric passports contain chips with information about the holder’s face that can be used to identify the individual. Facial recognition and fingerprint technology is also being trialled. UK Border Agency’s e-Borders programme will collect and analyse passenger and crew data for journeys to and from the UK ahead of travel.
Passengers on US-bound flights from countries designated by the US as “state-sponsors of terrorism” and other “countries of interest” are subject to special screening, unless specifically cleared. Cuba, Iran, Sudan and Syria, Afghanistan, Algeria, Iraq, Lebanon, Libya, Nigeria, Pakistan, Saudi Arabia, Somalia and Yemen are all on the list.
Boarding pass check
The final check before getting onto the aircraft is usually the boarding pass control which is often accompanied by one last check of the passport. Most airports have automatic readers that verify the pass to confirm that the passenger is boarding the flight that is carrying their checked-in luggage.