The CIA has thwarted an underwear bomb plot organized by al-Qaida, according to the Associated Press:
U.S. officials say the plot involved an upgrade of the underwear bomb that failed to detonate aboard a jetliner over Detroit on Christmas 2009. This new bomb was also built to be used in a passenger's underwear but contained a more refined detonation system.
The would-be suicide bomber was told to buy a ticket on the airliner of his choosing and decide the timing of the attack. It's not immediately clear what happened to the would-be bomber.