US Secretary of State Hillary Clinton said Tuesday an Al-Qaeda plot to blow up a US-bound plane with an underwear bomb was proof of the "perverse and terrible" lengths militants are willing to go to.
US officials said Monday that Al-Qaeda's branch in Yemen had planned to blow up the passenger plane near the first anniversary of Osama bin Laden's death on May 2.
The FBI said investigators had seized what seemed to be a revamped model of a bomb used in the Christmas Day plot of 2009, in which plastic explosive hidden in a Nigerian man's underwear failed to detonate on a plane headed for Detroit.
"The plot itself indicates that the terrorists keep trying... to devise more and more perverse and terrible ways to kill innocent people," Clinton said in New Delhi on the final day of a three-nation Asian tour.
"It is a reminder as to why we have to remain vigilant at home and abroad in protecting our nation and in protecting friendly nations and peoples like India and others," Clinton told reporters.
According to the White House and government agencies, the plot hatched by Al-Qaeda in the Arabian Peninsula (AQAP) was uncovered at an early stage and at no point was the public in danger.
AQAP has been linked to the 2009 Christmas plot and is also suspected of orchestrating a 2010 attempt to blow up cargo planes heading to the United States with explosives concealed in printer cartridges.