House and Senate Republicans are making a renewed effort to press the Obama administration about the timeline of events leading to the death of four Americans at a U.S. consulate in Libya two weeks ago.

The Republican chairmen of the House authorizing and appropriating committees wrote to President Barack Obama this morning, saying they would return from the campaign trail for more detailed classified briefings about the security situation at the American facility in Benghazi, Libya.

“While we appreciate your willingness to provide the House of Representatives with an interagency briefing last week, many of the members’ questions were left unanswered,” the Members wrote. “To that end, we are seeking additional information regarding the intelligence leading up to the attack, the security posture of our embassy, the role former Guantanamo Bay detainees may have played, as well as the way forward in Libya and, indeed, the region.”

House Armed Services Chairman Buck McKeon (R-Calif.), joined by his colleagues from the Foreign Affairs, Intelligence and Judiciary panels as well as several appropriators involved in funding the Defense and State departments, signed the letter, which criticized earlier administration suggestions that the attack in Libya was the result of an angry mob of protesters.

Libyan President Mohamed Megariaf this morning disputed claims that the protests in Benghazi were in response to an anti-Muslim film.

“Reaction should have been, if it was genuine, should have been six months earlier. So it was postponed until the 11th of September,” Megariaf told NBC’s “Today” show, saying he believed the timing was connected to the anniversary of 9/11.

Republican Sens. John McCain (Ariz.) Lindsey Graham (S.C.), Kelly Ayotte (N.H.) and Ron Johnson (Wis.) pressed U.S. Ambassador to the United Nations Susan Rice in a separate letter released today.

The Senators questioned public statements that Rice made Sept. 16 suggesting the Benghazi incident was the result of a “spontaneous reaction” rather than a carefully planned terrorist strike.

“By the date of your comments, it was already clear that the attack in Libya was a terrorist attack, and that heavily armed and well trained attackers appeared to have prepared for an opportunity to attack U.S. interests. We also knew that there is a significant network of al Qaeda affiliated groups and other terrorists in eastern Libya, some of whom have attacked western interests in the last few months,” the Senators wrote. “Yet, you repeatedly asserted the implausible explanation that the attack in Benghazi was a spontaneous reaction to the video despite growing evidence to the contrary.

“If the murder of four American diplomats is not ‘an expression of hostility’ it is difficult to know what would be,” they added.

Asked about the Libyan intelligence on Air Force One, White House Press Secretary Jay Carney said information provided reflected what was believed.

“Over the course of the past two weeks, this administration has provided as much information as it has been able to. We made clear that our initial assessment and interim reports were based on information that was available at the time,” Carney said.

The House lawmakers also questioned why the FBI appears to be the lead agency investigating the deaths of U.S. Ambassador to Libya Chris Stevens and the three others.

“This seems like a pre-9/11 mindset – treating an act of war solely as a criminal matter, rather than also prioritizing the gathering of intelligence to prevent future attacks,” they wrote.

The FBI typically takes the investigative lead on attacks on Americans overseas.

Carney said both FBI and State Department investigations are ongoing.