Washington - The CIA thwarted an ambitious plot by al-Qaeda's affiliate in Yemen to destroy a US-bound airliner using a bomb with a sophisticated new design around the one-year anniversary of the killing of Osama bin Laden, The Associated Press has learned.
The plot involved an upgrade of the underwear bomb that failed to detonate aboard a jet over Detroit on 25 December 2009.
This new bomb was also designed to be used in a passenger's underwear, but this time al-Qaeda developed a more refined detonation system, US officials said.
The FBI is examining the latest bomb to see whether it could have passed through airport security and brought down an aircraft, officials said.
They said the device did not contain metal, meaning it probably could have passed through an airport metal detector. But it was not clear whether new body scanners used in many airports would have detected it.
The would-be suicide bomber, based in Yemen, had not yet picked a target or bought his plane tickets when the CIA stepped in and seized the bomb, officials said. It's not immediately clear what happened to the alleged bomber.
Assurance
The operation unfolded even as the White House and department of homeland security assured the American public that they knew of no al-Qaeda plots against the US around the anniversary of bin Laden's death on 2 May.
"We have no credible information that terrorist organisations, including al-Qaeda, are plotting attacks in the US to coincide with the anniversary of bin Laden's death," White House press secretary Jay Carney said on 26 April.
On 1 May, the department of homeland security said, "We have no indication of any specific, credible threats or plots against the US tied to the one-year anniversary of bin Laden's death."
The AP learned about the thwarted plot last week, but agreed to White House and CIA requests not to publish it immediately because the sensitive intelligence operation was still under way.
Once officials said those concerns were allayed, the AP decided to disclose the plot on Monday despite requests from the Obama administration to wait for an official announcement on Tuesday.
US officials, who were briefed on the operation, insisted on anonymity to discuss the case, which the US has never officially acknowledged.
Master bomb maker
It's not clear who built the bomb, but, because of its sophistication and its similarity to the Detroit bomb, authorities suspected it was the work of master bomb maker Ibrahim Hassan al-Asiri.
Al-Asiri constructed the first underwear bomb and two others that al-Qaeda built into printer cartridges and shipped to the US on cargo planes in 2010.
Both of those bombs used a powerful industrial explosive. Both were nearly successful.
The operation is an intelligence victory for the United States and a reminder of al-Qaeda's ambitions, despite the death of bin Laden and other senior leaders.
Because of instability in the Yemeni government, the terrorist group's branch there has gained territory and strength. It has set up terrorist camps and, in some areas, even operates as a de facto government.
But along with the gains there also have been losses.
The group has suffered significant setbacks as the CIA and the US military focus more on Yemen.
On Sunday, Fahd al-Quso, a senior al-Qaeda leader, was hit by a missile as he stepped out of his vehicle along with another operative in the southern Shabwa province of Yemen.
$5m bounty
Al-Quso, 37, was on the FBI's most wanted list, with a $5m reward for information leading to his capture. He was indicted in the US for his role in the 2000 bombing of the USS Cole in the harbour of Aden, Yemen, in which 17 American sailors were killed and 39 injured.
Al-Quso was believed to have replaced Anwar al-Awlaki as the group's head of external operations.
Al-Awlaki was killed in a US air strike last year.
- AP