Former CIA director David H. Petraeus told Congress on Friday that the Sept. 11 attack on the U.S. mission in Benghazi, Libya, was clearly an act of terrorism, but he did not resolve the question of when the agency reached that conclusion, according to law­makers who attended the closed-door sessions.

Several members of the House and Senate intelligence committees who heard Petraeus’s testimony said that he indicated he believed immediately after the incident that it was a terrorist attack. That appeared to conflict with testimony he gave them three days after the attack, when he said it appeared to have begun as a “spontaneous” assault that was overtaken by “extremists.”

The timing of the CIA’s conclusion has become a contentious issue in Congress, where some prominent Republicans have charged that Susan Rice, the U.S. ambassador to the United Nations and President Obama’s leading candidate to become secretary of state, knowingly presented a whitewashed account in television appearances on Sept. 16.

Reading from administration talking points, Rice hewed to the “spontaneous” theory, saying that the attack began as a protest against an anti-Islamic video that was privately produced in the United States and was hijacked
by “opportunistic extremist
elements.” In the television interviews, she said this was the “best information” available, but stressed that the matter was under investigation.

Petraeus, who has not appear­ed in public since he resigned last week after revelations of an extramarital affair, avoided a swarm of reporters and photographers awaiting his arrival for the early morning hearings held in secret briefing rooms three floors underground in the U.S. Capitol Visitor Center.

“You can blame it on us. We wanted to spare him,” Sen. Dianne Feinstein (D-Calif.), who chairs the Senate panel, told reporters after Petraeus had left.

Rep. Peter T. King (R-N.Y.) said the House panel had only briefly discussed the former general’s affair with former Army officer Paula Broadwell and that Petraeus had assured them his resignation related only to that and not to the Benghazi attack.

“He realizes what he’s done [to] himself, and to the CIA,” King told Fox News. “He apologized, but once he got into his testimony, he was the same old General Petraeus.”

According to accounts provided by intelligence officials, the CIA concluded early on that Benghazi was a terrorist attack by definition, because any assault on a U.S. government installation with heavy weapons and substantial firepower could not be classified otherwise. The officials spoke on the condition of anonymity to discuss intelligence matters.

In the swirl of initial reporting about the attack, which killed Ambassador J. Christopher Stevens and three other Americans, two accounts made their way into the first round of analysis, the officials said. Reports from the ground in Libya described a demonstration at the Benghazi mission, similar to a large
anti-U.S. protest the same day outside the U.S. Embassy in Egypt.

At the same time, intelligence quickly uncovered links to militant groups, including associates of al-Qaeda. The administration did not make the terrorist links public until the Sept. 19 congressional testimony by Matthew G. Olsen, director of the National Counterterrorism Center.

Since then, the CIA and other intelligence analysts have settled on what amounts to a hybrid view, suggesting that the Cairo protest sparked militants in Libya, who quickly mobilized an assault on U.S. facilities in Benghazi.

The details about possible al-Qaeda involvement were not included in talking points initially used by both Petraeus and Rice because they were preliminary and were based on classified sources, intelligence officials said.

Critics of administration conduct have suggested that the White House excised any reference to terrorism for political reasons.

A senior U.S. official familiar with the drafting of the talking points said Friday that they “reflected what was known at the time” and “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.” In addition to concerns about classified sources, the official said, “when links were so tenuous — as they still are — it makes sense to be cautious before pointing fingers to avoid setting off a chain of circular and self-reinforcing assumptions.”

The use of the word “extremists” by both Petraeus and Rice in the days after the attack, the official said, was “meant to capture the range of participants. The controversy this word choice caused came as a surprise.”

In addition to an internal State Department inquiry, several House and Senate committees are investigating what happened before, during and after the incident. In a sharply worded letter Friday to Sen. John McCain (R-Ariz.) and others who have called for formation of a Watergate-style select committee, Senate Majority Leader Harry M. Reid (D-Nev.) said that standing committees were fully capable of examining the issue.

Reid accused the advocates of a special committee of manipulating Congress “in service of partisan agendas.”

“The elections are over,” he wrote. “It is time to put an end to the partisan politicization of national security and begin working together to strengthen our efforts to dismantle and destroy the terrorist networks that threaten us.”

But Petraeus did not appear to provide any answers. The former CIA chief, King said, “clearly believes that [the attack] did not arise out of a demonstration, that it was not spontaneous and it was clear terrorist involvement.”

Democrats noted that this was hardly a revelation, and that it had been the administration’s public position since Sept. 19, three days after Rice’s interviews.

Petraeus’s testimony, Rep. Adam B. Schiff (D-Calif.) said, “completely debunked the conspiracy theory that this was some political machination coming out of the White House.”

Greg Miller contributed to this report.