Two weeks after the September 11 attacks, the Federal Bureau of Investigation connected the hijackers to al-Qaeda, 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. 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.