Hamburg cell
The Hamburg cell (German: Hamburger Zelle; Arabic: خلية هامبورغ, Khaliyyat Hāmbūrġ) was 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 to crash them into American landmarks.