FBI agents made a brief visit to Benghazi this week to examine the scene of the consulate terror attack that killed four Americans -- after being delayed for weeks because of security concerns.
Fox News confirms that the FBI team, which had been held up for weeks getting into the eastern Libya city, arrived in Benghazi to gather evidence and has since left.
"The FBI continues to coordinate with the U.S. Departments of State, Justice, and Defense, as well as the Libyan government, and other agencies in furtherance of the investigation into the deaths of Ambassador Stevens, Glen Doherty, Sean Smith, and Tyrone Woods," the FBI said in a statement. "As this is an ongoing investigation, we have no further information to provide."
A Libyan official told AFP that the team worked for three hours collecting evidence.
As the FBI investigates, an independent panel has been established by the State Department to review what went wrong. That review, though, could take months and U.S. lawmakers were starting to express frustration after their requests for more information were rebuffed as Secretary of State Hillary Clinton urged lawmakers to wait for the conclusion of an internal review.
Sens. Bob Corker, R-Tenn., and Johnny Isakson, R-Ga., on Wednesday renewed their demand for documents after Clinton declined to hand over the cables they initially requested. The House Intelligence Committee has not received any documents from the department either, Fox News has learned.
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"We hope that in the next few days you follow through with transmitting information requested by members of Congress," Corker and Isakson wrote in a letter to Clinton. "In particular, we renew our request for all communications between the diplomatic mission in Libya and the State Department related to the security situation to be transmitted to the Senate Foreign Relations Committee without delay."
Clinton raised concerns among some Republican lawmakers that she was pushing off the review's conclusions until after the election, as she named a five-member "Accountability Review Board" to examine the deadly Sept. 11 attack on the U.S. Consulate in Benghazi.
"No one wants to determine what happened that night in Benghazi more than the president and I do. No one is more committed to ensuring it doesn't happen again, and nobody will hold this department more accountable than we hold ourselves because we serve with and we knew the four men we lost," Clinton said Wednesday.
But she did not address specific allegations that diplomats had warned in advance of security concerns.
The House Oversight and Government Reform Committee is planning to hold a hearing on Oct. 10. In a letter to Clinton on Wednesday, Chairman Darrell Issa, R-Calif., asked that the department provide two witnesses -- Eric Nordstrom, who was stationed in Libya until June, and Deputy Assistant Secretary for International Programs Charlene Lamb, a Washington official involved in reviewing security requests.
The hearing comes as the department's review is just getting underway. Among those on the panel are Adm. Mike Mullen, former chairman of the Joint Chiefs of Staff, and retired U.S. Ambassador Thomas Pickering, who served as America's top diplomat in several countries.
Language published in the Federal Register this week declared that the board will submit its findings "within 60 days of its first meeting, unless the Chair determines a need for additional time."
Rep. Jason Chaffetz, R-Utah, expressed concern that the State Department's findings would be pushed off until "after the election."
"There are clear signs that (there were) security concerns in Libya and other embassies around the world, and what they were doing is diminishing security in the name of normalizing relations," Chaffetz told Fox News.
Issa and Chaffetz, in an earlier letter to Clinton, detailed several attacks in Benghazi in the lead-up to the strike that they suggested should have been warning signs.
Further, they claimed sources told them that diplomats made "repeated requests" for additional security but were denied.
New signs also were emerging this week that officials were receiving guidance that the attack was coordinated in the immediate aftermath of the strike despite public comments to the contrary.
The New York Times, which first reported that the U.S. was tracking suspects, reported that, according to one official, spy agencies were intercepting communications from militant Ansar al-Shariah fighters boasting to someone with an Al Qaeda affiliate.
Reuters also reported that the Obama administration had "about a dozen" intelligence reports within hours of the attack suggesting Al Qaeda-tied militants were involved.
Fox News reported last week that intelligence officials were picking up that it was a terror strike within 24 hours.
Still, top administration officials in the week after the attack insisted it was a "spontaneous" reaction to protests over an anti-Islam film. That film was driving demonstrations across the Middle East and North Africa, but lawmakers and others were saying from the start that Libya was a different situation despite the initial claims of the Obama administration.
Fox News' Catherine Herridge contributed to this report.