WASHINGTON – American commandos who burst into Osama bin Laden's  room and killed him feared he was reaching for a nearby weapon, US officials said.

Several weapons were found in the room where the terror chief died, including AK-47 assault rifles and side arms, the officials said. They spoke on condition of anonymity as they offered the most recent in a series of increasingly detailed and sometimes-shifting accounts of bin Laden's final minutes after a decade on the run.

After two days of shifting accounts of the dramatic raid, White House press secretary Jay Carney said he would no longer provide details of the 40-minute operation by the team of elite Navy SEALs.

That left unresolved numerous mysteries, prominent among them an exact accounting of bin Laden's demise. Officials have said he was unarmed but resisted when an unknown number of commandos burst into his room inside the high-security compound.

The officials who gave the latest details said a US commando grabbed a woman who charged toward the SEALs inside the room. They said the raiders were concerned that she might be wearing a suicide vest.

Administration officials have said bin Laden's body was identified by several means, including a DNA test. Members of Congress who received a briefing during the day said a sample from the body killed at the compound in Pakistan was compared to known DNA from bin Laden's mother and three sons.

Attorney General Eric Holder told Congress the operation was "entirely lawful and consistent with our values" and justified as "an action of national self-defense." Noting that bin Laden had admitted his involvement in the events of nearly a decade ago, he said, "It's lawful to target an enemy commander in the field."

Holder also said the team that carried out the raid had been trained to take bin Laden alive if he was willing to surrender. "It was a kill-or-capture mission," he said. "He made no attempt to surrender."

Bin Laden had evaded capture for nearly a decade, and officials said he had currency as well as two telephone numbers sewn into his clothing when he was killed, suggesting he was prepared to leave his surroundings on a moment's notice if he sensed danger.

Administration officials said the two dozen SEALs involved in the operation were back at their home base outside Virginia Beach, Va., and the extensive debriefing they underwent was complete. Saluted as heroes nationwide, they remained publicly unidentified because of security concerns.

In addition to bin Laden's body, the SEALs helicoptered out of the compound with computer files, flash drives, DVDs and documents that intelligence officials have begun analyzing in hopes the information will help them degrade or destroy the network bin Laden left behind.