NEW YORK, Feb 10: The US Aviation authorities chose to ignore at least 52 warnings prior to Sept. 11, 2001, from their own security experts about potential Al Qaeda attacks , including some that mentioned airline hijackings or suicide attacks, a declassified 9/11 commission report says.

The report obtained by the New York Times takes the US Federal Aviation Authority (FAA) to task for failing to pursue domestic security measures that could conceivably have altered the events of Sept. 11, 2001, like toughening airport screening procedures for weapons or expanding the use of on-flight air marshals.