Agents seized a more high-tech version of the pants bomb that failed to detonate on a jet over Detroit on Christmas Day 2009.
Terror chiefs wanted to blow up a plane full of Americans to mark the one-year anniversary of the death of former leader Osama Bin Laden.
CIA agents are believed to have seized the bomb in Yemen in the last ten days. It is not known what happened to the would-be suicide bomber.
The US said the new bomb did not contain metal — meaning it probably would have passed through an airport metal detector.
But the device featured a more sophisticated detonator than the first version and included a powerful industrial explosive.
Authorities suspect it was designed by Ibrahim Hassan al Asiri — who created the first pants bomb in 2009. That device caused a fireball but failed to explode on a Delta Airlines flight carrying 289 Christmas Day travellers.
Would-be bomber Umar Farouk Abdulmutallab was jailed for life in February this year. The operation was last night hailed as an intelligence victory by US President Barack Obama.
White House spokeswoman Caitlin Hayden said, “The President thanks all intelligence and counter-terrorism professionals involved for their outstanding work.”
Defence Secretary Leon Panetta added: “This incident makes it clear this country has to remain vigilant. We will do everything necessary to keep America safe.”
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