The revelation that militants sought to attack an airliner
with an improved "underwear bomb" in a plot foiled by US and
allied authorities shows their determination to build bombs
that can pass through airport security, US officials said.
The Obama administration said on Monday that authorities in
the Middle East recently seized an underwear bomb which they
believe al Qaeda's Yemen-based affiliate had intended to give
to a suicide bomber to blow up an airliner bound for the US
or another Western country.
US officials told Reuters the device was seized within the
last 10 days.
The plot was detected in its early stages, and no US airliner
was ever at risk, officials said.
Yet the aborted plot shows that the Yemen-based group, al
Qaeda in the Arabian Peninsula (AQAP), remains intent on
attacking the United States or its allies, and is continuing
to evolve its weapons and tactics.
One official said the latest underwear bomb to be discovered
appeared to be similar to the work of fugitive Saudi militant
Ibrahim Hassan al-Asiri, who US sources believe is a
bomb-maker working with AQAP.
US officials said it had design features which were somewhat
more sophisticated than a bomb used in two attempted attacks
In the first incident, a man equipped with a bomb in his
underwear tried to attack Prince Mohammed bin Nayef, a senior
Saudi Arabian counter-terrorism official. The bomber killed
himself in the attack but the prince survived.
On Christmas Day that year, a Nigerian-born militant who had
spent time in Yemen, Umar Farouk Abdulmutallab, tried to
detonate a bomb sewn into his underpants as his flight from
the Netherlands to Detroit began its descent in US airspace.
The device burst into flames but its explosive charge did not
detonate. Abdulmutallab was subdued by fellow passengers and
was later jailed by US authorities.
IMPROVED BOMB MODEL
One official said the device seized in the latest
investigation used what was supposed to be an improved or
redesigned mechanism intended to ensure that the explosive
"While similar, a preliminary review of this device shows
that it has some significant differences from the device used
in the Christmas Day attack. It is clear that AQAP is
revamping its bomb techniques to try to avoid the causes of
the failure of the 2009 device," the official added.
Like the bombs used in the two previous attempted attacks,
the latest device was non-metallic, officials said.
Senator Dianne Feinstein, chairman of the Senate intelligence
committee, said: "I congratulate the CIA for thwarting this
reported plot by AQAP to destroy a US-bound airliner using a
specific type of bomb that is of new design and very
difficult to detect by magnetometer."
US and European officials said that the newly-revealed plot
was part of continued efforts by AQAP to design devices which
could get through airport security.
A senior US official said the group might be eager to mount
an attack following US operations that killed al Qaeda leader
Osama bin Laden and AQAP's American-born chief Anwar
"AQAP is probably feeling pressure to conduct a successful
attack to, from their perspective, avenge the deaths of bin
Laden and Awlaki," a senior US official said.
PLOT NO THREAT TO PUBLIC
Caitlin Hayden, a spokeswoman for the National Security
Council, said President Barack Obama had been informed of the
plot in April and had been regularly updated about it.
"While the President was assured that the device did not pose
a threat to the public, he directed the Department of
Homeland Security and law enforcement and intelligence
agencies to take whatever steps necessary to guard against
this type of attack," Hayden said.
US officials declined to say where the underpants bomb was
seized or by whom, but indicated it was either inside Yemen
itself or a nearby country. Several officials stressed that
the bomb never made it aboard an aircraft.
A senior US official said: "We disrupted this plot well
before it was ever a threat to the United States."
"We believe AQAP produced the device, and we believe it was
intended to be used by a suicide bomber on an aircraft," the
official said, adding: AQAP remained "committed to striking
targets in Yemen, Saudi Arabia, the Homeland, and Europe."
The FBI said in cooperation with security and intelligence
partners overseas "an improvised explosive device (IED)
designed to carry out a terrorist attack has been seized
abroad. The FBI currently has possession of the IED and is
conducting technical and forensics analysis on it."
It said initial investigation showed the bomb was similar to
devices used by al Qaeda in the Arabian Peninsula (AQAP) in
attempted attacks on planes and in assassinations attempts.
US officials said AQAP had also been working to design
explosive devices which could be implanted in would-be
suicide bombers and there were doctors willing to perform the
They said implanted bombs were more likely that those built
into clothing to defeat airport security though the impact
may be weaker.