The Associated Press says the U.S. Central Intelligence Agency(CIA) thwarted a plot by Al-Qaeda's affiliate in Yemen to blow up a U.S.-bound airliner around the one-year anniversary of the killing of Osama bin Laden.

The AP quoted U.S. officials saying Monday that the plot involved an upgrade of the underwear bomb that failed to detonate aboard a jetliner over Detroit on Christmas in 2009.

The officials said the new bomb was also designed to be used in a passenger's underwear, but this time Al-Qaeda developed a more refined detonation system.