U.S. officials say they have stopped an al-Qaida bomb plot intended to destroy an airliner heading for the United States.
Authorities in Washington say the al-Qaida branch in Yemen intended to put a suicide bomber aboard a U.S.-bound jet with explosives concealed in the attacker's underwear.
They say the plot was detected and the bomb was seized before any plane was at risk.
The White House National Security Council said in a statement Monday that U.S. President Barack Obama was first informed about the plot in April and has received regular updates about the situation. It said the president was assured that the device did not pose a threat to the public.
Addressing reporters Monday, U.S. Defense Secretary Leon Panetta declined to comment on specific classified operations. However, he said the incident makes clear the United States must remain vigilant against possible attacks.
The Associated Press says the would-be attacker is based in Yemen and the plot was to be carried out around the one-year anniversary of the U.S. raid that killed Osama bin Laden.
Officials say the bomb was a redesign of an explosive that was used to try to blow up an airplane bound for Detroit from Amsterdam in 2009.