U.S officials said that four American military personnel were detained by the Libyan government on Friday and held in custody for several hours before being released.
State Department spokeswoman "Jen Psaki" said President Barack Obama's administration was looking into the incident, but confirmed that "all four U.S military personnel being held in Libyan government custody have been released", adding that "the United States valued its relationship with the new Libya".
A U.S defense official said the Americans appeared to have been checking possible evacuation routes for the U.S embassy in Tripoli.
Psaki said "we have a strategic partnership based on shared interests and our strong support for Libya's historic democratic transition".
On Sept. 11, 2012, a militant attack in Benghazi killed U.S Ambassador "Chris Stevens" and three other Americans.