Officials in the Netherlands arrested two men at Amsterdam’s Schiphol Airport on Tuesday on suspicion of planning a terrorist attack.
Dutch authorities never release the names of criminal suspects but an American TV network identified two US men of Yemeni origin as those who had been detained.
One of them started his journey in Birmingham, Alabama where he was stopped by customs officers.
They found mobile phones, knives and watches taped to a medicine bottle in his check-in baggage.
It is not illegal to carry these items in the hold of a passenger plane.
He was allowed to travel on to Chicago as no explosives were found.
US officials raised the alarm when he checked his luggage onto a flight to Yemen but instead boarded a plane for Amsterdam with the other suspect.
They say the trip could have been a ‘dry run’ for a planned terrorist attack.
Dutch police are currently questioning the pair.