US-bound travellers at Amsterdam's airport have been undergoing body searches in line with a global US request for increased security after a Nigerian transit passenger boarded a flight to Detroit apparently intending to blow up the aircraft, authorities said.
The additional security measure at the boarding gate for US flights came as agencies in the Netherlands, Nigeria, Yemen and the United Kingdom joined forces to uncover the route and connections of Umar Farouk Abdul Mutallab, who officials said told US authorities he tried to set off an incendiary device as his Northwest Airlines Flight 253 was descending.
"The extra measures apply worldwide on all flights to the US as of now and for an indefinite period," said Judith Sluiter, spokeswoman for the Dutch National Co-ordinator for Counterterrorism.
Dutch airport, airline and military police officials declined to discuss Mutallab's case while the investigation is under way.
US congressman Peter King said Mutallab boarded a flight in Lagos for the Amsterdam connection.
The Nigerian landed on his KLM Boeing 777 before dawn and had a layover of nearly three hours at Schiphol Airport before the Northwest Airbus A330 lifted off for the nine hour flight to Detroit.
The general alert level at the airport was not immediately raised after the incident, and security procedures for other flights remained unchanged, Sluiter said.
Schiphol, one of Europe's busiest airports with a heavy load of transit passengers from Africa and Asia to North America, strictly enforces European security regulations including only allowing small amounts of liquid in hand luggage that must be placed inside clear plastic bags.
The airport has been testing full body scanners for about a year that allow security staff to see the outline of a passenger's body beneath their clothes, and intend to roll out a more complete programme next year, said airport spokeswoman Mirjam Snoerwang.
Mutallab's leg was badly burned after his abortive attempt to cripple the plane, an indication that he had strapped the incendiary device onto his leg. It was unclear, however, when he attached the device or whether the body scanner would have caught it.