The 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 from different Arab countries 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. Background On November 1, 1998, future-hijackers Mohamed Atta, Marwan al-Shehhi, and Ramzi bin al-Shibh moved into an apartment (two bedrooms, one living room, one kitchen) together on Marienstraße. Here they formed the secretive Hamburg cell, which also included other minor participants in the 9/11 plot. They met together three or four times a week to discuss their anti-American and anti-Israeli views, and to decide how best to fight for their cause. As late as 1999, the four core members of the group had intended to wage jihad in Chechnya, where Islamic jihadists were rebelling against Russia. The 9/11 Commission Report notes in Chapter 5 that "according to bin al-Shibh [who is now in U.S. custody], a chance meeting on a train in Germany caused the group to travel to Afghanistan instead. An individual named Khalid al Masri (or Khalid al-Masri) approached bin al-Shibh and Shehhi (because they were Arabs with beards, bin al-Shibh thinks) and struck up a conversation about jihad in Chechnya. When they later called Masri and expressed interest in going to Chechnya, he told them to contact Abu Musab in Duisburg, Germany. Abu Musab turned out to be Mohamedou Ould Slahi, a significant al-Qaeda operative who, even then, was well known to U.S. and German intelligence, though neither government apparently knew he was operating in Germany in late 1999." Bin al-Shibh, Shehhi and Jarrah visited Slahi in Duisburg, where he convinced them that it would be best to train in Afghanistan first, because further experience would be useful, and anyway it was difficult at that time to get into Chechnya. Slahi instructed them to travel to Karachi, Pakistan,