The United States has asked airlines worldwide to tighten security after a Nigerian tried to blow up a US airliner he boarded in Amsterdam, Dutch authorities said Saturday.
Officials said they were probing how the man smuggled explosives through security at Amsterdam-Schipol airport.
"We are investigating from where he came, through which security barriers he passed and his travel itinerary," Judith Sluiter, spokeswoman for the national coordinator against terrorism (NCTB) in The Hague told reporters.
She refused to confirm reports that he arrived in Amsterdam on a KLM flight from Lagos.
Meanwhile the NCTB said in a statement that US authorities had asked airline companies to take extra security measures."The extra measures will apply throughout the world on all flights to the United States for an unlimited duration," it said.
"It will involve, for example, frisking passengers and extra checks on hand baggage," Sluiter told reporters.
The extra measures came into force on Saturday morning in the Netherlands, which received a formal request from the US authorities during the night, she said.
The Nigerian who claimed to have links with Al-qaeda tried to detonate an explosive device aboard the plane as started its descent to Detroit on Friday before being overpowered by fellow passengers and crew.
He was arrested after the Airbus A 330 operated by Northwest Airlines, and originating from Amsterdam's Schiphol airport, landed.