U.S. probing whether Libya attack was extremist plot

President Barack Obama rushed 50 Marines to Libya to safeguard American personnel and critical facilities there, and ordered a worldwide review of security at diplomatic posts. The moves were made amid escalating worries that a deadly attack on the U.S. Consulate in Benghazi stemmed from a carefully planned extremist plot, not a spontaneous riot.

Even as Obama's National Security Council formally said it was too soon to "speculate" about the motives of those who killed four Americans, including Ambassador Chris Stevens, in Benghazi, other officials confirmed that U.S. intelligence was looking into the possibility of a carefully orchestrated assault.

"This was a well-armed, well-coordinated event, it had both indirect and direct fire, and it had military maneuvers that were all part of this very organized attack," House Intelligence Committee Chairman Mike Rogers, a Republican, told MSNBC. "That's concerning, so we are going to have to make sure, working with the Libyans hopefully, that these people are brought to justice very swiftly."

On a conference call organized by the State Department, officials told reporters an investigation was under way into the precise circumstances of the attack, which led to the first death of a U.S. ambassador in the line of duty since 1979.

Whether Stevens was targeted or merely in the wrong place at the wrong time, "we just are not in a position to say," a senior administration official said on the call, which was held on condition that the officials not be named.

Faced with multiple questions about the details of the attack as well as the possibility an al-Qaida-linked group might have been behind it, the officials said more details would be available "in coming days and weeks."

"There's going to have to be a full investigation, and presumably some of these things will come to light," said one senior official.

Another official on the call confirmed Obama's order of 50 Marines to Libya. He said they're from the Fleet Antiterrorism Security Team (FAST)—an elite unit tasked with protecting American officials and diplomatic facilities and, if necessary, overseeing evacuations. But the official declined to comment on a possible U.S. military role in the hunt for the perpetrators.