Two men remained in custody in the Netherlands on Tuesday after being arrested at Amsterdam’s Schiphol Airport on suspicion of planning a terrorist attack.
Dutch authorities have not identified the Yemeni-born suspects, who have not been formally charged.
“They were supposed to be travelling on to Sana’a in Yemen. The luggage of the men had ended up on an internal flight to Washington,” said Theo D’Anjou, a spokesman for the Dutch public prosecutor.
“In this luggage mobile phones were found taped, one phone was found taped to a plastic bottle. These phones were seized in the US and stayed there,” he added.
US officials raised the alarm when one of the men, who had travelled from Birmingham, Alabama, checked his bags onto a Washington flight at Chicago’s O’Hare airport before boarding a plane for Amsterdam with the other suspect.
Police are questioning the two men to establish whether they were carrying out a dry run for a later attack.
The White House has said neither of the pair was on any US terror watch list.
Under Dutch law, they can be held without charges for up to six days.
The investigation continues.