Updated: 4:50 p.m.

The leaders of the Senate Homeland Security and Governmental Affairs Committee requested a slew of documents from the Obama administration today as part of the panel’s investigation into last month’s attack on Americans in Benghazi, Libya.

Chairman Joe Lieberman (I-Conn.) and ranking member Susan Collins (R-Maine) announced one week ago that they planned to investigate the incident, as well as statements made by the administration in the immediate aftermath of it that have become an issue on the presidential campaign trail.

In separate letters to Secretary of State Hillary Rodham Clinton, Defense Secretary Leon Panetta and Director of National Intelligence James Clapper, the Senators ask for classified documents and briefings about the circumstances of the Sept. 11 attack, which killed four Americans including the U.S. ambassador to Libya.

“We seek to understand the specific circumstances as a means to determine whether actions are necessary, either by Congress or the executive branch, to prevent and protect against similar attacks in the future, to address broader policy or operational issues, and ultimately to improve our security without degrading our government’s ability to carry out diplomatic activity around the world,” Lieberman and Collins write.

The Senators press Clinton on statements made by U.S. Ambassador to the United Nations Susan Rice in a series of television appearances on the Sunday after the attack in which Rice made statements that have since been publicly criticized.

“If any of Ambassador Rice’s public statements on September 16 were inaccurate, please explain the reason for the inaccuracies and identify the persons most knowledgeable about how and why inaccurate information was publicly conveyed,” they write to Clinton.

Rice said Sept. 16 that the Benghazi incident was believed to be a “spontaneous reaction” rather than a carefully planned terrorist strike. The public explanation at the time suggested it was tied to a protest of an anti-Muslim film, even though details had emerged that pointed to a more coordinated attack.

Senate Intelligence Chairman Dianne Feinstein (D-Calif.) raised questions about Clapper’s actions following the attack in a Wednesday interview with a San Francisco television station.

“I think what happened was the Director of intelligence, who is a very good individual, put out some speaking points on the initial intelligence assessment,” Feinstein told CBS 5. “I think that was possibly a mistake.”

“There’s no question but that it was a terrorist attack, there is no question but that the security was inadequate, and I think that there is no question that we need to work on our intelligence,” she said.

In a separate letter, three Republican Senators wrote to Clapper, CIA Director David Petraeus and Deputy National Security Advisor John Brennan pushing for a response to a query they made last week about the Benghazi situation.

Armed Services ranking member John McCain (Ariz.) led fellow GOP national security hawks Sens. Lindsey Graham (S.C.) and Kelly Ayotte (N.H.) in the follow-up letter.

“We have important responsibilities to our constituents, who are demanding clear answers to the questions we sent to you. Your lack of response is inhibiting our ability to perform our duties on behalf of our fellow citizens,” they wrote. “We therefore continue to seek answers to our questions and expect a reply as soon as possible.”

In addition to asking about the intelligence situation that has received the most attention, Lieberman and Collins ask Clinton if the diplomatic security budgets for the past three fiscal years have been fully expended and what the effect of unobligated funds might be.

Democrats have criticized House Republicans for proposing a budget that could reduce funding for embassy security, but Republicans continue to talk about the issue. It is likely to resurface on Monday night when President Barack Obama meets Republican challenger Mitt Romney for their final debate. The debate, which will be moderated by Bob Schieffer of CBS News, is supposed to focus entirely on foreign affairs.

Two top Republicans on the House Oversight and Government Reform Committee wrote to President Barack Obama today, and they provided him with 166 pages of documents and photographs that they have obtained during their own investigation into the security situation in Libya.

In their letter, Chairman Darrell Issa (Calif.) and National Security Subcommittee Chairman Jason Chaffetz (Utah) raised questions about security in the aftermath of a separate assassination attempt against the British ambassador in the country.

“Information supplied to the committee by senior officials demonstrates that not only did the administration repeatedly reject requests for increased security despite escalating violence, but it also systematically decreased existing security to dangerous and ineffective levels,” Issa and Chaffetz wrote. The House panel held a politically charged hearing on Libya last week.

House Oversight and Government Reform ranking member Elijah Cummings (D-Md.) was quick to respond to Issa and Chaffetz, accusing them of politicizing the Benghazi attack in advance of Monday’s presidential debate. Cummings replied to Issa in his own letter.

“It seems obvious that your goal in sending a public letter at this time is to release the most negative and distorted view possible of the attack in Benghazi ahead of the Presidential debate on Monday evening,” Cummings wrote. “This is particularly disturbing given requests by Ambassador Stevens’ family not to politicize his death as part of the campaign.”