STR/AFP/GettyImages

ABC News' John R. Parkinson and Sunlen Miller report:

The attack that killed four Americans in the Libyan consulate began as a spontaneous protest against the film "The Innocence of Muslims," but Islamic militants who may have links to Al Qaeda used the opportunity to launch an attack, CIA Director David Petreaus told the House Intelligence Committee today according to one lawmaker who attended a closed-door briefing.

Rep. Dutch Ruppersberger, the top Democrat on the House Intel committee, said Petraeus laid out "a chronological order exactly what we felt happened, how it happened, and where we're going in the future."

"In the Benghazi area, in the beginning we feel that it was spontaneous - the protest- because it went on for two or three hours, which is very relevant because if it was something that was planned, then they could have come and attacked right away," Ruppersberger, D-Md., said following the hour-long briefing by Petraeus. "At this point it looks as if there was a spontaneous situation that occurred and that as a result of that, the extreme groups that were probably connected to al Qaeda took advantage of that situation and then the attack started."

Petraeus did not speak to reporters on his way in or out of the briefing. When he left the meeting, the former four-star general was trailed by about a dozen intelligence officials and a couple of Capitol police officers.

Members of the Senate Armed Services Committee were also briefed today by Defense Secretary Leon Panetta and Vice Chair of the Joint Chiefs Admiral James Winnefeld. But senators emerging from that private briefing reported that they believed the attack in Libya was premeditated.

"It was a terrorist attack organized and carried out by terrorists," Sen. John McCain, R-Ariz., the top Republican on the committee said, adding that about 15 "al Qaeda or radical Islamists" were armed with rocket propelled grenades and other lethal weapons.

"This was a calculated act of terror on the part of a small group of jihadists, not a mob that somehow attacked and sacked our embassy," McCain said. "People don't go to demonstrate and carry RPGs and automatic weapons."

"I don't think any of us are clear yet about who carried out these attacks in Libya, but from all that I've heard the murderous attacks on Libya that resulted in the death of four Americans were not accidental," Sen. Joe Lieberman, I-Conn., added. "They were not just some kind of coincidental protests to this film, this anti-Muslim film. They were a well-planned and professional terrorist attack against the U.S. consulate in Benghazi."

This morning, President Obama notified congressional leaders that he had deployed troops "equipped for combat" to Libya and Yemen to defend U.S. citizens and property, pursuant to the War Powers Resolution.

"It's just common sense that in view of the situation that we're looking at right now, we will see enhanced security anywhere across the world where we see the protests," Rep. Michele Bachmann, R-Minn., said after attending the briefing with Petraeus. "We've seen how quickly this one began, and how quickly it turned violent and I think that's something that we have to be aware of and deal with."

Rep. Pete King, another Republican on the House Intel committee and the chairman of the Homeland Security panel, said that regardless of whether al Qaeda coordinated the attack on the consulate in Libya, "we are very concerned that this could spread" to other countries across the region.

"We're talking about a very hostile area of the world in many cases, a very turbulent part of the world where there are many enemy forces, very disparate forces, many type of jihadists," King, R-N.Y., said. "Like Libya there's many militias that are still there, heavily armed, they do have an al Qaeda presence. You put all that together, it's very combustible, and it can be many countries besides Libya and Egypt."

King also criticized the Obama administration's policies and echoed GOP presidential candidate Mitt Romney by saying Obama has sent "a very mixed message, a confusing message" that has "weakened our position in the Middle East."

"President Obama's policies since the summer of 2009 I think have not been helpful to the United States in the Middle East. It's weakened our position in the Middle East," he said. "You combine that with the way [President Obama] treats [Israeli Prime Minister Benjamin] Netanyahu in Israel and the pulling troops out of Iraq without getting a status of forces agreement [with] the apologies. You put it all together and I think that what you saw this week is in many ways a logical result of all of that."

Across Capitol Hill, McCain was slightly more blunt in his criticism of President Obama.

"Everything is unraveling in that part of the world because the United States is weak," McCain said. "This president does not understand the importance of American leadership."