Al Qaeda Leader Behind Northwest Flight 253 Terror Plot Was Released by U.S. Man believed behind Northwest Airlines plot was set free.

Dec. 28, 2009  -- THIS PIECE HAS BEEN CORRECTED SINCE IT WAS FIRST PUBLISHED.

One of the four leaders allegedly behind the al Qaeda plot to blow up a Northwest Airlines passenger jet over Detroit was released by the U.S. from the Guantanamo prison in November 2007, according to American officials and Department of Defense documents. Al Qaeda claimed responsibility for the Northwest bombing in a Monday statement that vowed more attacks on Americans.

American officials agreed to send the terrorist from Guantanamo to Saudi Arabia, where he entered into an "art therapy rehabilitation program" and was set free, according to U.S. and Saudi officials. ABC News described his enrollment in the art therapy program in a January report. (See video to the left.)

Guantanamo prisoner prisoner #372, Said Ali Shari was sent to Saudi Arabia on Nov. 9, 2007, according to the Defense Department log of detainees who were released from American custody.

The Saudi national has since emerged in leadership roles in Yemen, according to U.S. officials and the men's own statements on al Qaeda propaganda tapes.

ABCNews.com reported Monday in error that former Guantanamo prisoner #333, Muhamad Attik al-Harbi, was one of four leaders of the al Qaeda group that claimed responsibility for the attempted bombing.

Al-Harbi, who now goes by the name Muhamad al-Awfi, turned himself in to the Saudi government in Februrary 2009 and therefore could not have played a direct role in organizing the attempt to bring down Northwest flight 253.

Al-Harbi appeared in a propaganda tape released by the group in January 2009. According to published reports, he surrendered to Saudi security forces one month later in February 2009, well before the August arrival in Yemen of accused underwear bomber, Umar Farouk Abdulmutallab.

According to the group's own statements and U.S. officials, the second former Guantanamo prisoner, Said Ali Shari, continues as a commander of the al Qaeda group, which U.S. officials say poses the most direct, operational threat to U.S. and western citizens.

Both of the former Guantanamo detainees appear on a January 2009 video along with the man described as the top leader of al Qaeda in Yemen, Abu Basir Naser al-Wahishi, formerly Osama bin Laden's personal secretary.

In its Monday statement claiming responsibility for the Northwest bombing, Al Qaeda in the Arabian Peninsula called bombing suspect Umar Farouk Abdulmutallab a "hero" and a "martyr" and lauded him for beating U.S. intelligence.

The two-page written claim included a photo of Abdulmutallab and boasted of Al Qaeda's success in designing "advanced explosive packages" that can pass through airport screening undetected.

The statement also asks for attacks upon Americans in the Arabian peninsula, and promises further attacks on the American people.

Abdulmutallab: Northwest Airlines Bomb Suspect

The suspected bomber, 23-year-old Umar Farouk Abdulmutallab, told FBI agents he was trained for his Christmas Day mission in Yemen by top leaders of al Qaeda who provided him with the explosive materials.

"The so-called rehabilitation programs are a joke," a U.S. diplomat said in describing the Saudi efforts with released Guantanamo detainees.

Saudi officials concede its program has had its "failures" but insist that, overall, the effort has helped return potential terrorists to a meaningful life.

One program gives the former detainees paints and crayons as part of the rehabilitation regimen.

A similar rehabilitation program in Yemen was stopped because so many of the detainees quickly joined with al Qaeda or its affiliates, the official said.

The increased role of al Qaeda in Yemen, which joined with the Saudi al Qaeda unit, has underscored the problem of how to best handle the repatriation of detainees at Guantanamo.

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