WASHINGTON -- The State Department said yesterday it never concluded that the consulate attack in Libya stemmed from protests over an American-made video ridiculing Islam, raising further questions about why the Obama administration used that explanation for more than a week after assailants killed the U.S. ambassador and three other Americans.

The revelation came as new documents suggested internal disagreement over appropriate levels of security before the attack, which occurred on the 11th anniversary of the Sept. 11 terror attacks on the United States.

Briefing reporters ahead of a hotly anticipated congressional hearing today, State Department officials provided their most detailed rundown of how a peaceful day in Benghazi devolved into a sustained attack that involved multiple groups of men armed with weapons such as machine guns, rocket-propelled grenades and mortars over an expanse of more than a mile.

But asked about the administration's initial -- and since retracted -- explanation linking the violence to protests over an anti-Muslim video circulating on the Internet, one official said, "That was not our conclusion." He called it a question for "others" to answer, without specifying.

The attack has become a major issue in the presidential campaign. Republican candidate Mitt Romney, in his latest foreign policy address on Monday, called it an example of President Barack Obama's weakness in foreign policy matters, noting: "As the administration has finally conceded, these attacks were the deliberate work of terrorists."

The administration counters that it has provided its best intelligence on the attack, and that it refined its explanation as more information came to light. But five days after the attack, Obama's UN ambassador, Susan Rice, gave a series of interviews saying the administration believed the violence was unplanned and that extremists with heavier weapons "hijacked" the protest and turned it into an outright attack.

She has since denied trying to mislead Congress, and a concurrent CIA memo obtained by The Associated Press cited intelligence suggesting the demonstrations in Benghazi "were spontaneously inspired by the protests at the U.S. Embassy in Cairo" and "evolved into a direct assault" on the diplomatic posts by "extremists." Alongside defining the nature of the Benghazi attack, Congress is looking into whether adequate security was in place.

According to an email obtained by the AP, the top State Department security official in Libya, Eric Nordstrom, told a congressional investigator he had argued for more security in the weeks before Ambassador Chris Stevens, a State Department computer specialist and two former Navy SEALs were killed. But department officials instead wanted to "normalize operations and reduce security resources," he wrote.

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