There can be no doubt that those who carried out the attacks on 9/11 did so believing that they were doung the will of Allah.
There can be no doubt that they were believing the teachings of the Koran.
There can be no doubt that they were Muslims.
If you are in doubt regarding these statements, then read the Koran for yourself. It is freely available here:
Number killed in attack on New York, in the Twin Towers and in aircraft that crashed into them: 2,823
Number of people who died when United Airlines flight 93, from Newark, New Jersey, to San Francisco, California, crashed in rural southwest Pennsylvania: 45
Number of people who died when American Airlines flight 77, from Washington to Los Angeles, crashed into the Pentagon: 64
Number of peole killed in the Pentagon: 125
They shall grow not old, as we that are left grow old:
Age shall not weary them, nor the years contemn.
At the going down of the sun and in the morning
We will remember them.