One year after the Sept. 11, 2012 terrorist attacks on Americans in Benghazi, Libya, no arrests have been reported but the Justice Department says investigators have made "very significant progress."
Four U.S. personnel, including U.S. Ambassador to Libya Christopher Stevens, were killed in mob assaults that moved from a U.S. diplomatic compound to a nearby CIA facility over a period of eight hours.
Last month, government officials confirmed that sealed criminal charges have been filed against suspects. They are said to include Ahmed Khattalah, who gave interviews in Benghazi with several news organizations admitting he was at the scene of the attacks but insisting he was not the "ringleader." Khattalah also said that nobody from the U.S. government had attempted to question him.
Sen. Lindsey Graham, R-S.C., and other Republican members of Congress recently sent a letter urging the new FBI Director James Comey to make Benghazi a top priority. Graham said that intelligence operatives have told him they have leads on suspects "but can't get approval to go after them."
A spokesman for the Justice Department tells CBS News that "the success of this investigation is a top priority" but would not provide details on its progress "to preserve its integrity."
White House spokesman Jay Carney, in a statement released Tuesday night, said, "We remain committed to bringing the perpetrators of the Benghazi attacks to justice and to ensuring the safety of our brave personnel serving overseas."
Benghazi remains a dangerous place, with militant groups continuing to attack offices of the relatively weak central government. Marking the one-year anniversary of the attack on the U.S. buildings, a bomb went off Wednesday outside a Foreign Ministry office in the city, causing significant damage but no confirmed deaths.
The top Democrat on the House Oversight Committee, Rep. Elijah Cummings, D-Md., told CBS News: "Although progress in bringing to justice the perpetrators of the Benghazi attacks may not be as rapid as we may want, I am confident that our law enforcement and national security officials around the world are fully committed to this goal."
The Obama administration continues to keep a great deal of information under wraps citing an ongoing investigation, national security and other reasons. The secrecy is an ongoing point of contention with Republicans in Congress.
Tuesday, the House Oversight Committee sent a letter to Secretary of State John Kerry demanding the Bengahzi survivors be made available for interviews with Congress or else they may be subpoenaed.
According to the letter, the State Department told Congress on Aug. 23 that "it was not prepared to support the request for transcribed interviews." If that doesn't change within two weeks, committee Chairman Darrell Issa, R-Calif., said "I will have no alternative but to consider the use of compulsory process."
The FBI, CIA, Director of National Intelligence, Defense Department, State Department and National Security Agency have rejected or failed to answer multiple Freedom of Information (FOI) requests made by CBS News, as well as appeals of the denials. The agencies cite exemptions related to ongoing investigations or national security.
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