The CIA and other intelligence agencies recently thwarted an attempt to bring down a US-bound airline by the al-Qaida branch in Yemen, US counterterrorism officials have confirmed.
The plot, hatched by al-Qaida in the Arabian Peninsula (AQAP), targeted a passenger jet in an echo of a failed attempt to bomb a Detroit-bound jet in 2009.
During the 2009 Christmas plot, a plastic explosive hidden in the underwear of Umar Farouk Abdulmutallab, failed to detonate on a plane which was heading to Detroit.
According to the officials, the new bomb was an upgrade of the underwear bomb and the plan was to carry out the attack on the first anniversary of the US raid that killed Osama bin Laden, though the airline or a target was not chosen.
The plot was uncovered abroad at an early stage before it posed any threat to the airlines and a non-metallic explosive device which was meant to be used by a suicide bomber was discovered, according to the FBI.
"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," senator Dianne Feinstein, who heads the Senate Intelligence Committee, said.
The officials did not reveal the fate of the alleged bomber and maintained that both the device and the intended user were no longer a threat.
"What this incident makes clear is that this country has to continue to remain vigilant against those that would seek to attack this country. And we will do everything necessary to keep America safe," said defence secretary Leon Panetta.
President Barack Obama was briefed about the incident in April, according to deputy spokeswoman for the National Security Council Caitlin Hayden.
"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," said Hayden in a statement.
The latest plot highlights the vulnerability of the aviation sector at the hands of terrorists and tightening of the screening at airports including the layered approach.
"These layers include threat and vulnerability analysis, pre-screening and screening of passengers, using the best available technology, random searches at airports, federal air marshal coverage and additional security measures both seen and unseen," the AFP quoted Department of Homeland Security spokesman Matt Chandler as saying.
In another incident, a senior AQAP operative wanted for his role in the USS Cole bombing was killed by an air strike in Yemen on Sunday, it has been reported.
Fahd al Quso, 37, was killed in a US drone attack while riding in a vehicle in Rafdh district in Shabwa province.