What organization did the terrorists on 9/11 belong to?
Responsibility for the September 11 attacks
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Two weeks after the September 11 attacks, the Federal Bureau of Investigation connected the hijackers to al-Qaeda,[1] a global, decentralized terrorist network. In a number of video, audio, interview and printed statements, senior members of al-Qaeda have also asserted responsibility for organizing the September 11 attacks.[2][3][4] It is believed that Osama bin Laden, Khalid Sheikh Mohammed, and Mohammed Atef were the ones who plotted the attacks after meeting together in 1999.[5] It is also believed Khalid Sheikh Mohammed was the one who planned the attacks[5] and that Atef was the one who organized the hijackers.[5]