http://www.washingtonpost.com/world/national-security/us-evacuates-embassy-in-libya-citing-militia-violence/2014/07/26/54e3ca24-14ca-11e4-98ee-daea85133bc9_story.htmlThe U.S State Department determined to avoid another Benghazi, ordered the evacuation of all personnel from it's embassy in Tripoli, Libya to Tunisia, due to what John Kerry described as "freewheeling militia violence". In addition The State Department has issued a travel advisory on Libya.
The United States is not the only country suspending diplomatic operations in Tripoli, as Turkey has also suspended diplomatic operations in Libya.