Though no group has explicitly claimed responsibility, the militant Islamic al-Qaeda group has praised the attacks and the group's leaders have hinted at their involvement in the incidents. Indeed, shortly after the attacks, the United States government declared them and their leader, Osama bin Laden, as the prime suspects. In 2004, the U.S. government commission investigating the attacks officially concluded that the attacks were conceived and implemented by al-Qaida operatives. [1]
Important information about the planning and execution of the attacks by al-Qaeda came to light following the capture of two of its members - Khalid Shaikh Mohammed and Ramzi Binalshibh - in separate raids in 2002 and 2003, and in an exclusive interview with al Jazeera journalist Yosro Fauda in September 2002.
Interrogations allegedly revealed that Khalid Mohammed was the instigator and prime organizer of the attacks. The first hijack plan that Mohammed presented to the leadership of al-Qaeda called for several airplanes on both east and west coasts to be hijacked and flown into targets. Mohammed's plan evolved from an earlier foiled plot known as Operation Bojinka which called for ten or more airliners to be bombed in mid-air or hijacked for use as missiles. Osama bin Laden was aware of these plans, and used his authority to gradually scale them down to an operation with four planes.
Shortly before the US presidential election in 2004, in a taped statement, bin Laden publicly acknowledged al-Qaida's involvement in the attacks on the U.S, and admitted his direct link to the attacks. He said that the attacks were carried out because "we are a free people who do not accept injustice, and we want to regain the freedom of our nation."
Bin Laden had categorically denied involvement in two previous statements in 2001[2], before his admission in the taped statement, in which he said
While I was looking at these destroyed towers in Lebanon, it sparked in my mind that the tyrant should be punished with the same and that we should destroy towers in America, so that it tastes what we taste and would be deterred from killing our children and women.âOsama bin Laden