In 2008, U.S. Ambassador to Libya J. Christopher Stevens warned in a diplomatic cable about a growing jihadist group in Derna, operating not far from Benghazi.
Stevens was killed this week in an attack that U.S. sources tell CNN was planned by a pro-al Qaeda group of extremists.
In his 2008 missive, Stevens wrote about the group, apparently operating in the port city of Derna.
"One Libyan interlocutor likened young men in Derna to Bruce Willis' character in the action picture "Die Hard", who stubbornly refused to die quietly," Stevens wrote.