More bombers are on their way to target America, the Nigerian al-Qaeda suspect charged with trying to blow up a United States airliner has told the FBI, setting alarm bells among the intelligence and security apparatus here.

Umar Farouk Abdulmutallab told the FBI that “there were more just like him in Yemen and would strike soon,” the ABC News reported, quoting officials familiar with the investigation.

A tape released by al Qaeda leaders in Yemen four days before the failed attempt to blow up the plane, said: “we are carrying bomb to hit the enemies of god.”

Abdulmutallab, 23, was arrested soon after his failed bid to ignite explosives inside the Amsterdam-Detroit Northwest Airlines flight 253 on Christmas Day with nearly 300 people on board.

The explosive was identified as PETN – pentaerythritol tetranitrate, which was concealed in his underwear.

According to news reports, Abdulmutallab told the FBI that he was trained for more than a month in Yemen, given 80 grams of the explosive cleverly sewn into his underpants, that went undetected by standard security screening.

“They know that this is a weakness and an Achilles’ heel in our airport security system,” said ABC News consultant and former counterterrorism czar Richard Clarke.

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