U.S. authorities released pictures of three men it said were present during the September 11, 2012 attack on the U.S. mission in eastern Libya, saying it wanted to question them.
The Federal Bureau of Investigation's website did not say whether the three men -- all of whom appear to be carrying guns in the pictures -- are suspects in the attack that killed four Americans, including Ambassador Chris Stevens.
"The FBI is now asking Libyans and people around the world for additional information related to the attacks," the federal law enforcement agency said.
"We are seeking information about three individuals who were on the grounds of the U.S. Special Mission when it was attacked. These individuals may be able to provide information to help in the investigation," it said.