U.S. officials are searching for vehicle bombs that al Qaeda wants to use to attack the U.S. Embassy in Yemen and potentially other targets, a senior U.S. official told ABC News today.
Nearly two dozen U.S. embassies in the Middle East and North Africa were shut down Sunday after U.S. intelligence intercepted communications between the leadership of al Qaeda's Yemen-based affiliate, al Qaeda in the Arabian Peninsula (AQAP), and the leader of core al Qaeda in Pakistan, Ayman al-Zawahiri, the man who took over after Osama bin Laden's death in May 2011. The embassies will remain closed all week, the State Department said.
"The part that is alarming is the confidence they showed while communicating and the air of certainty," an official said Sunday referring to the intercepted communications, adding that AQAP appeared to have a media plan for after the attack.
Prior to the senior U.S. official's comments today, U.S. intelligence had been trying to identify both the potential target - airlines, U.S. diplomatic facilities or trains among others - and method of the attack - everything from a new and improved underwear bomb, to bombs surgically implanted into suicide bombers, to vehicles packed with explosives.
Sunday on "This Week," Rep. Dutch Ruppersberger, D-Md. - the ranking member of the House Intelligence Committee - said the intercepted communications showed the threat is "very credible."
"What we have to do now is the most important issue, is protect Americans throughout the world," Ruppersberger said.
The senior U.S. official told ABC News that in the course of investigating the new threat, intelligence officials also discovered communications between al Qaeda affiliates and at least one person in the U.S. The communications were electronic and by mail, but the official said it's unclear how significant the link is. It is not believed to be connected to the current plot in Yemen, the official said.
Today White House spokesperson Jay Carney declined to say whether the U.S. homeland was a target for the suspected plot, saying it is "emanating from and maybe directed towards the Arabian Peninsula, but it is beyond that, potentially."
Top U.S. officials have previously declared that al Qaeda core has been decimated as U.S. counter-terror operations have killed some of its high-level leaders, but only to see al Qaeda's affiliates emerge as greater threats to U.S. interests.
"As al Qaeda core has been diminished through the efforts of the United States and our allies, affiliate organizations, including in particular al Qaeda in the Arabian Peninsula, have strengthened," Carney said.