U.S. Deputy Secretary of State William Burns speaks during a news conference in Tripoli Libya April 24, 2014. Burns, the most senior U.S. official to visit Libya since a deadly 2012 attack on a U.S. ... more 
U.S. Deputy Secretary of State William Burns speaks during a news conference in Tripoli Libya April 24, 2014. Burns, the most senior U.S. official to visit Libya since a deadly 2012 attack on a U.S. compound there, said on Thursday Libya was facing a severe challenge from an increase in extremist violence. REUTERS/Ismail Zitouny (LIBYA - Tags: POLITICS) less 
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Reuters | Photo By ISMAIL ZITOUNY / REUTERS
Thu, Apr 24, 2014 6:52 AM EDT