In the early 1990s , Ali Mohamed , a former United States Army Special Forces supply sergeant , returned to Afghanistan , where he gave training in al-Qaeda camps . According to FBI special agent Jack Cloonan , in one of Mohamed 's first classes were Osama bin Laden , Ayman al-Zawahiri , and other al-Qaeda leaders . According to the '' San Francisco Chronicle '' , he was involved in planning the 1998 bombings of US embassies in Africa
1998 bombings of US embassies in Africa
1998 United States embassy bombings
International counter-terrorism activities of the CIA