This is an old story but in light of what happened in Benghazi, it deserves to be reiterated. A 2007 West Point Combating Terrorism Center study found that about 1 in 5 suicide bombers in Iraq were recruited in Libya. Libya has been a terrorist hotbed for a long time. This was reported a number of times during the Libyan Rebellion in 2011.
Direct Link to West Point study: