09/12/2012 05:32 pm ET Updated Sep 13, 2012

Libya Attack: Consulate Battle Raged For 4 Hours, Official Says

WASHINGTON -- The battle over the U.S. consulate in Benghazi, Libya, where four American diplomats lost their lives Tuesday night, lasted for approximately four hours, a senior administration official said in a press briefing Wednesday afternoon.

Three American staffers -- including Ambassador J. Christopher Stevens, who later died in the assault -- were inside the main building of the compound around 10 p.m. local time, when the facility started taking small-arms fire from outside, the official said.

Within 15 minutes, the attackers had breached the outside wall of the consulate and began targeting that main building, soon setting it on fire. Initial reports had suggested that the attackers used rocket-propelled grenades, something the administration official could not confirm.

The three Americans in the building -- a U.S. regional security officer, Ambassador Stevens, and Sean Smith, a Foreign Service information technology officer who also later died -- "became separated from each other due to heavy dark smoke while trying to evacuate," the official said.

"The RSO [regional security officer] made it outside, and then he and other security personnel returned into the burning building in an attempt to rescue Chris and Sean," the official said. "At that time they found Sean, he was already dead, and they pulled him from the building. They were unable, however, to locate Chris before being driven from the building due to heavy fire and smoke."

U.S. security officers, working together with Libyan guards and a local militia friendly to the Americans, were not able to retake control of the compound until after 2 a.m. local time, the official said. Ambassador Stevens' body was later delivered to American officials at the airport, sometime near dawn, but officials were unable to confirm when exactly he had died and how.

Recent reports have indicated that the attack on the compound in Benghazi may have been planned by a radical Islamic terrorist group, rather than being the result of protests that got out of hand, as many first assumed. The U.S. Embassy in Cairo was also stormed amid protests, driven by a little-known film that depicts the Prophet Muhammad in a negative light and has circulated on the Internet, but no Americans were wounded during that incident.

The official who was briefing reporters Wednesday emphasized repeatedly that the administration's information was still composed of sketchy "first reports" and said that times and details "could very well change as we get a better understanding."