Al Qaida is suspected of playing a role because a video posted on the Internet the evening before featured Ayman al Zawahiri, Osama bin Laden’s successor, calling for revenge for the death of his second in command, Abu Yahya al Libi, a Libyan cleric, who was killed in a June 4 CIA drone strike in Pakistan’s tribal region.

Two senior Republican lawmakers questioned the administration’s version of the attack, with Sen. Lindsey Graham, R-S.C., saying it “defies common sense.” He called for a congressional investigation.

“It is imperative that Congress conduct an investigation into this matter as the two scenarios are vastly different in terms of scope and depth,” Graham said in a statement on Monday. “A planned and coordinated assault points loudly to a security lapse, and the problems associated with such a scenario are much deeper than a violent riot over a film.”

“It is my belief, as stated by the Libyan president, that this was a coordinated attack by al Qaida or like-minded groups,” said Graham, a member of the Senate Armed Services Committee.

Rep. Mike Rogers, R-Mich., the chairman of the House Intelligence Committee, said he was told by Pentagon and CIA officials that they were “only moderately confident that it was a spontaneous event because there are huge gaps in what we know.”

“I think it’s just too early to make that conclusion,” he told Fox News on Sunday.

Rogers, a former FBI agent, said that the attack “seemed to be military style, coordinated,” featured “indirect fire coordinated with direct-fire rocket attacks,” and took place on the 11th anniversary of al Qaida’s strikes on the United States. The assailants also “repelled a fairly significant Libyan force that came to rescue” the consulate.

“It just has all the markings of an al Qaida-style event,” he said.

Aaron Zelin, an expert on Islamic extremist groups at the Washington Institute for Near East Policy, said he agreed that the attack was most likely planned in advance because the assailants launched a second attack on the consulate’s safe house, which U.S. officials have been referring to as the annex.

“Not only was there the attack on the consulate, but they knew where that safe house was,” he said. “They had to have some kind of reconnaissance ahead of time.”

“I think that has more to do with the anniversary of 9/11 than anything else,” he said.

He noted that Ansar al Shariah leaders have denied ordering the attack. But they didn’t condemn it, either, he said, adding that it appeared that group members were present “in their individual capacities.”

At the same time, he said there are “no known operational links” between Ansar al Shariah and any al Qaida-affiliated groups operating in the region.

Tommy Vietor, a White House spokesman, said in an email that the administration’s version is “our assessment based on the information available.”

“I can’t speak to the factual basis for statements made by Libyan officials,” he said. He declined to comment on the statements by Rogers and Graham.

Susan Rice, the U.S. ambassador to the United Nations, laid out the administration’s version on Sunday talk shows.