The attempted bombing of the Northwest Airlines flight from Amsterdam, with 278 passengers, has highlighted security weaknesses in three countries.
Authorities are particularly concerned that the accused bomber, 23-year-old Umar Farouk Abdulmutallab, was already registered as a suspected terrorist but not prevented from flying or put on an official "watch-list" because of insufficient information.
Abdulmutallab, who was badly burned during the incident on Christmas Day (Washington time), was charged in a Detroit hospital yesterday with attempting to destroy an aircraft.
He is accused of detonating an explosive device attached to his body. Investigators have found the device contained PETN, also known as pentaerythritol, the same plastic explosive used by convicted al-Qa'ida "shoe bomber" Richard Reid in December 2001.
Flights to the US were already subject to random searches and explosives-detection tests, but US authorities have told airlines worldwide that all passengers must now be patted down by security staff and have their carry-on baggage searched prior to boarding.
As well as being required to be seated one hour prior to arrival, passengers will be prevented from accessing overhead lockers and cabin baggage or having blankets, pillows or belongings on their laps during this time.
Security at airports around the world was significantly tightened after al-Qa'ida-backed terrorist attacks in the US on September 11, 2001, brought down four aircraft and killed almost 3000 people.
Reid's failed attempt to destroy a US-bound flight using a bomb in his shoe prompted authorities to require passengers to take off their shoes during airport screening.
In the latest attack, the accused Nigerian man is said to have passed security undetected by hiding PETN detonation materials on his body that were too small to detect.
After possibly mixing powder and a small amount of fluid in one of the jet's toilets and returning to his seat, Abdulmutallab covered himself with a blanket and allegedly set off the device.
Passengers who witnessed the incident as the plane approached Detroit Metropolitan Airport said they saw a man on fire and an apparent explosion.
He was overpowered by passengers and brought to the front of the aircraft.
Abdulmutallab was charged while sitting in a wheelchair in a hospital conference room at the University of Michigan Health Centre, where he is being treated for third-degree burns.
He faced two charges: attempting to destroy an aircraft and placing a destructive device on board an aircraft.
According to reporters, he was asked if he understood the charges. He replied in English: "Yes, I do."
British police yesterday conducted searches at various addresses in London, including the basement flat where Abdulmutallab had lived when he was a student.
Abdulmutallab's father, a prominent Nigerian former banker, revealed yesterday that he had alerted the US embassy in Nigeria's capital, Abuja, six months ago about the possible risk posed by his son's "radicalisation and associations". Alhaji Umaru Mutallab, is understood to have raised concerns that his son may have travelled to Yemen and feared that he wanted to join "some kind of jihad".
The US government appears to have followed up the alert by creating a file in the Terrorist Identities Datamart Environment. But Abdulmutallab had already been granted a two-year tourist visa in June last year by the US embassy in London. He was not placed on a "no-fly list" nor "watch-listed" on the day of the incident.
Abdulmutallab was a mechanical engineering student in London. He is then believed to have asked his family for further support to study in Dubai, but may have travelled to Yemen.
He is alleged to have told FBI investigators after his arrest that he received training and explosive materials from terrorists in Yemen linked to al-Qa'ida. This information is still to be verified.
Amsterdam's Schipol aiport, where Abdulmutallab boarded for Detroit, is one of the world's most high-security airports.
Schipol is understood to be testing a new generation of screening equipment, called backscatter body scanners, although it is not known at this stage if this device was used for Abdulmutallab's flight.
While some reports said yesterday explosive materials were hidden on his body, one claimed more specifically that powder was sewn into his underpants.
It was also claimed he mixed the powder with liquid from a syringe, part of which was found near his seat after the explosion. The small quantity may not have been sufficient to do wider damage to the plane.
If explosives were attached to Abdulmutallab's body, the only way to have detected them would have been a body search.
Several Republicans yesterday accused Barack Obama of failing to take notice of early signs of terrorism. Pete Hoekstra, the senior Republican on the House Intelligence Committee, said: "We came very, very close to losing that plane."
The US President, who is holidaying with his family in Hawaii, was briefed on the incident and did not return home early to Washington.