Hamburg cell

The Hamburg cell (German: Hamburger Zelle; Arabic: خلية هامبورغ, Khaliyyat Hāmbūrġ) were a terrorist cell of Islamist extremists living in Hamburg, Germany, around the late 1990s. They helped plan al-Qaeda's terrorist attacks against the United States on 11 September 2001 (9/11), in which 19 men hijacked four airliners to try and crash them into American landmarks.

In 1999, the cell left Germany to join the Chechen jihadists fighting Russia in the Second Chechen War, but redirected to Afghanistan to meet al-Qaeda's leadership. They then worked on the hijacking plan at a Hamburg apartment owned by the cell's ringleader, Mohamed Atta. Twelve men were members: Atta, Marwan al-Shehhi, and Ziad Jarrah—who died as the hijacker-pilots of American Airlines Flight 11, United Airlines Flight 175, and United Airlines Flight 93, respectively—plus Abdelghani Mzoudi, Ahmed Taleb, Mamoun Darkazanli, Mohammed Haydar Zammar, Mounir el-Motassadeq, Naamen Meziche, Ramzi bin al-Shibh, Said Bahaji, and Zakariya Essabar.

When the cell dissolved and 9/11 was carried out, Bahaji, Essabar, and Meziche disappeared to Afghanistan and Pakistan, while the others were captured or arrested in various countries. Most were imprisoned, while Mzoudi was acquitted, and bin al-Shibh and Darkazanli never faced full trials. The U.S. accused Mohamedou Ould Slahi, a Mauritanian businessman, of helping the cell visit al-Qaeda in Afghanistan. He was arrested, sent to the U.S. detention camp at Guantanamo Bay in Cuba, and tortured by camp officials. After 14 years, he was freed when a court found him to be innocent. Bin al-Shibh, held at Guantanamo for 19 years, was also tortured there.