As an airstrike in Yemen killed another five al Qaeda terrorists Thursday, warnings were sounded in Washington about the continued threat the group has on the U.S.
Ibrahim al-Asiri, the man considered to be al Qaeda's best bombmaker, is still at large. The U.S. believes he's using cameras, computers, and even pets to hide explosives.
"(He's) very innovative in trying to find some way to get a bomb onto an airplane that will evade detection from airport screeners," explained Seth Jones, senior political scientist at the Rand Corporation.
"We want to make sure that he doesn't have the opportunity ... to build any device whatsoever and impart that knowledge to anyone else who wants to build these devices," Rep. Mike Rogers, R-Mich., said.
FBI Director Robert Mueller has already told lawmakers that al Qaeda in Yemen is still a significant threat.
Testifying before Congress Wednesday, he said that despite the disruption of a recent Yemeni plot to take down a U.S.-bound airliner, the United States remains vigilant against future attacks.
"Let me begin with the threat from terrorism, which remains our top priority," Mueller told lawmakers. "Al Qaeda affiliates, especially al Qaeda in the Arabian Peninsula, represent the top counter-terrorism threat to the nation."
The plot was foiled by a CIA spy who infiltrated an al Qaeda cell in Yemen, discovered the scheme, and then stole the bomb.
"It's quite an accomplishment to be able to pass yourself off as an al Qaeda terrorist to the terrorists, when in fact you're working for a U.S. or allied intelligence agency," Richard Clarke, a national security official for the Clinton administration, said.
Meanwhile, more details are emerging on the extent of the damage done to al Qaeda by that intelligence operation.
It not only gave the United States a look at al Qaeda's latest bomb, it also led to last weekend's drone strike that killed Egyptian-born Ibrahim al-Banna, a key al Qaeda figure.
Al-Banna is believed to have been the chief of external operations in Yemen and personally met with the would-be bomber.