Some individuals go abroad to a region containing extremism , predominantly Pakistan , but also Iraq , Afghanistan , Yemen or Somalia . In the case of the London Underground bombers , Mohammad Sidique Khan , the operational leader of the cell , received military and explosives training at a camp in Malakand , Pakistan in July 2003 . Later he took Shezad Tanweer to Karachi , Pakistan , in late 2004 to February 2005 where they crossed the border to receive training at al-Qaeda camps in Afghanistan
London Underground bombers
7 July 2005 London bombings
Domestic terrorism