US News

Bomber had enough explosives in underwear to rip hole into plane

Call them Jihad Jockeys.

These are the explosives-packed underpants worn by Umar Farouk Adbulmutallab (here in a mug shot released yesterday by the US Marshals Service) when he tried to bring down a flight over Detroit – and managed only to set his crotch on fire.

The frighty whities came with a special pouch sewn by al Qaeda’s finest seamstresses. In it was a condom packed with 80 grams of PETN, a compound that’s a key ingredient in the plastic explosive Semtex. The suicide bomber tried to set it off by using a hypodermic needle to inject it with a powerful acid, while trying to hide his actions by putting a blanket on his lap.

The photos of the undies, obtained by ABC News, show they were only singed in Abdulmutallab’s failed efforts to send the Airbus 380 careering to the ground.

It was not immediately clear what the underpants were made of.

Experiments by security officials found as little as 50 grams of PETN could blast a hole in the side of a plane.

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Tragedy was averted only because the detonator, an acid-filled syringe, melted and did not make proper contact with the PETN.

The PETN burned, rather than detonated, sending a spout of flames more than six feet high and severely burning Abdulmutallab — but causing minimal damage to the plane.

The syringe melted completely.

The improvised explosive device chillingly shows how al Qaeda has adapted its techniques to thwart metal detectors and other security.

Convicted shoe bomber Richard Reid packed his sole with 50 grams of PETN on his Dec. 21, 2001 flight from Paris to Miami.

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Reid failed in his attempt to detonate the PETN with a book of matches. Since then, shoe removal has been a standard part of airport screenings.

The astounding revelation came as these other developments were reported:

* US Marshals Service released a photo of Abdulmutallab, taken sometime after his arrest. His head cocked to the side, he stares without emotion at the camera.

* The fumbling crotch bomber, a rich 23-year-old Nigerian schooled in London, where he turned into a raving radical, warned authorities he’s one in a long line of madmen planning to wage jihad against the United States.

Abdulmutallab, who almost succeeded in detonating the powerful explosives he’d stashed in his underpants aboard Northwest Flight 253, mockingly told FBI agents other extremists in Yemen will strike soon, ABC News reported.

Yet President Obama yesterday inexplicably called him an “isolated extremist.”

* Obama ordered a complete review of the terrorist watch list, as well as airport screening methods.

* Abdulmutallab said he wanted to blow up the Airbus 300 over the Detroit airport so there’d be no doubt it was an act of terrorism, ABC News reported.

* He purposely chose seat 19A, a window seat next to the wing and above the fuel tank, because he thought it would maximize the damage from the bomb, ABC also reported.

* Department of Homeland Security Secretary Janet Napolitano backtracked from her comments Sunday that “the system worked.”

* In May 2009, a Justice Department Inspector General report found problems with the FBI’s management of the terror watch list.

It noted “in 32 of the 216 [15 percent] terrorism investigations we reviewed, 35 subjects of these investigations were not nominated to the consolidated terrorist watch list, contrary to FBI policy.”

* British and Dutch authorities hunted for Abdulmutallab’s associates and potential accomplices.

* Yemeni authorities said Abdulmutallab was in their country from August until early December to study Arabic in a school in San’a, the capital; they said he’d studied there previously.

* Abdulmutallab’s father confirmed he had warned US authorities about his son.

Also yesterday, Obama made his first public comments on the incident, saying it was “absolutely critical that we learn from this incident and take the necessary measures to prevent future acts of terrorism.”

“We do not yet have all the answers about this latest attempt, but those who would slaughter innocent men, women and children must know that the United States will do more than simply strengthen our defenses,” he said in Hawaii.

A more detailed account of Abdulmutallab’s plot and whereabouts also emerged yesterday.

He was placed on a list of 550,000 other names, the Terrorist Identities Datamart Environment Database, after his father alerted US authorities on Nov. 19 that his son may have fallen in with Islamic terrorists.

But the State Department cable issued the next day to the National Counterterrorism Center and US embassies around the world had so little information, it was never acted on, ABC reported.

And nothing was done to cancel Abdulmutallab’s travel visa to the United States.

Nor was Abdulmutallab added to the Transportation Security Administration’s “selectee” list of 14,000 people who must be searched twice before boarding commercial aircraft, much less to the 4,000-name no-fly list.

The watch list was already subject to a scathing report in May by the Justice Department’s Inspector General, which found it to be horribly mismanaged and out of date.

Still, the vacationing president assured the country air travel is still safe, and then referred to the bomber as an “isolated extremist.”

US officials were well aware, however, that Abdulmutallab had connections to al Qaeda.

A source close to his family told the Sunday Trust of Abuja, Nigeria, that up to a few days ago, there had been communication between an American security official and Abdulmutallab’s father, Umaru.

“We were hopeful that they would find and return [Umar] home. It was while we were waiting for the outcome of their investigation that we arose to the shocking news of that day,” Abdulmutallab’s family said in a statement.

More details also emerged on how Abdulmutallab engineered his failed attack.

He was packing in his underpants 80 grams of PETN, a powerful component in plastic explosives — about 30 grams more than convicted shoe bomber Richard Reid attempted to use on a flight from Paris to Miami in December 2001.

Abdulmutallab’s bomb never properly detonated. It only caught fire, allowing a brave passenger to subdue him. With Tom Topousis & AP

cbennett@nypost.com