Hamburg cell ( ) or Hamburg terror cell ( ) was , according to U.S. and German intelligence agencies , a group of radical Islamists based in Hamburg , Germany that included students who eventually came to be key operatives in the 9/11 attacks . Important members included Mohamed Atta , who led the four hijacking teams in 2001 and piloted American Airlines Flight 11 ; Ramzi bin al-Shibh , who conspired with the other three members but was unable to enter the United States ; Marwan al-Shehhi , who piloted United Airlines Flight 175 ; and Ziad Jarrah , who piloted United Airlines Flight 93 and failed to hit a target in Washington , D.C. ( claimed by Khalid Sheikh Mohammed to have been the Capitol ) . Other members included Said Bahaji , Zakariya Essabar , Mounir el-Motassadeq , and Abdelghani Mzoudi
American Airlines Flight 11
American Airlines Flight 11
Hamburg cell