WASHINGTON — David H. Petraeus, the former director of the Central Intelligence Agency, told lawmakers on Friday that classified intelligence reports revealed that the deadly assault on the American diplomatic mission in Libya was a terrorist attack, but that the administration refrained from saying it suspected that the perpetrators of the attack were Al Qaeda affiliates and sympathizers to avoid tipping off the groups.
Mr. Petraeus, who resigned last week after admitting to an extramarital affair, said the names of groups suspected in the attack — including Al Qaeda’s franchise in North Africa and a local Libyan group, Ansar al-Shariah — were removed from the public explanation of the attack immediately after the assault to avoiding alerting the militants that American intelligence and law enforcement agencies were tracking them, lawmakers said.
In his first public appearance since he resigned last week, Mr. Petraeus testified before the House and Senate Intelligence Committees in back-to-back closed-door hearings as lawmakers from both parties continued to wrestle with questions about the Obama administration’s handling of the Sept. 11 attacks in Benghazi that killed Ambassador J. Christopher Stevens and three other Americans and why its public portrayal conflicted with the intelligence agencies’ classified assessments.
“They knew right away that there were terrorists involved in the operation,” said Representative C. A. Dutch Ruppersberger of Maryland, the top Democrat on the House Intelligence Committee.
During his testimony, Mr. Petraeus expressed regret for his affair. Lawmakers did not ask him about it. In addition to what the administration knew about assailants, they focused their questions on possible security lapses at the diplomatic compound in Benghazi, particularly given a spate of attacks this year in Benghazi against the American Mission, the British ambassador’s convoy and the Red Cross.
State Department officials have said five diplomatic security officers were at the mission on Sept. 11, including two traveling with Mr. Stevens. They were initially up against more than 50 fighters, armed with automatic rifles and rocket-propelled grenades, who easily breached the compound and set fire to it.
Senator Marco Rubio, Republican of Florida, said Mr. Petraeus’s testimony showed that “clearly the security measures were inadequate despite an overwhelming and growing amount of information that showed the area in Benghazi was dangerous, particularly on the night of Sept. 11.”
But many of the questions from lawmakers dealt with how the intelligence services and the administration over all responded to a request from the House committee for unclassified talking points about what happened, in advance of a closed briefing by Mr. Petraeus on Sept. 14, three days after the attack.
The issue took on added resonance after Republicans criticized the ambassador to the United Nations, Susan E. Rice, for suggesting on Sunday talk shows five days after the assault that the siege in Benghazi was a spontaneous protest rather than an opportunistic terrorist attack.
Democrats leapt to Ms. Rice’s defense on Friday, saying she was simply following the unclassified talking points provided to her. “I really think Ambassador Rice is being treated unfairly,” said Senator Dianne Feinstein, a California Democrat who leads the Intelligence Committee.
The talking points initially drafted by the C.I.A. attributed the attack to fighters with Al Qaeda in the Islamic Maghreb, the organization’s North Africa franchise, and Ansar al-Shariah, a Libyan group, some of whose members have Al Qaeda ties.
Mr. Petraeus and other top C.I.A. officials signed off on the draft and then circulated it to other intelligence agencies, as well as the State Department and National Security Council.
At some point in the process — Mr. Petraeus told lawmakers he was not sure where — objections were raised to naming the groups, and the less specific word “extremists” was substituted.
“The fact is, the reference to Al Qaeda was taken out somewhere along the line by someone outside the intelligence community,” Representative Peter T. King, a New York Republican, said after the House hearing. “We need to find out who did it and why.”
After the hearings on Friday, administration officials disputed the notion that politics or other motives caused the changes.
“The points were not, as has been insinuated by some, edited to minimize the role of extremists, diminish terrorist affiliations, or play down that this was an attack,” said a senior official familiar with the drafting of the talking points. “There were legitimate intelligence and legal issues to consider, as is almost always the case when explaining classified assessments publicly.”
Some intelligence analysts worried, for instance, that identifying the groups could reveal that American spy services were eavesdropping on the militants — a fact most insurgents are already aware of. Justice Department lawyers expressed concern about jeopardizing the F.B.I.’s criminal inquiry in the attacks. Other officials voiced concern that making the names public, at least right away, would create a circular reporting loop and hamper efforts to trail the militants.
Democrats said Mr. Petraeus made it clear the change had not been done for political reasons to aid Mr. Obama. “The general was adamant there was no politicization of the process, no White House interference or political agenda,” said Representative Adam B. Schiff, Democrat of California.
Senator Mark Udall, Democrat of Colorado, said that Mr. Petraeus explained to lawmakers that the final document was put in front of all the senior agency leaders, including Mr. Petraeus, and everyone signed off on it.
Ms. Feinstein, read the final unclassified talking points to reporters:
“The currently available information suggests that the demonstrations in Benghazi were spontaneously inspired by the protests at the U.S. Embassy in Cairo and evolved into a direct assault against the U.S. diplomatic post in Benghazi and subsequently its annex. There are indications that extremists participated in the violent demonstrations.
“This assessment may change as additional information is collected and analyzed and as currently available information continues to be evaluated.
“The investigation is ongoing, and the U.S. government is working with Libyan authorities to bring to justice those responsible for the deaths of U.S. citizens.”