Leaked emails sent by State Department officials two hours after the fatal attack began on the U.S. diplomatic compound in Benghazi, Libya, last month stirred new debate Wednesday about the Obama administration's shifting statements on the attack.

WASHINGTON — A series of three leaked emails sent by State Department officials beginning shortly after the fatal attack began on the U.S. diplomatic compound in Benghazi, Libya, last month — including one that alerted the White House Situation Room that a militant group had claimed responsibility for it — stirred new debate Wednesday about the Obama administration’s shifting positions on the attack.

The first email, sent about a half-hour after the assault began, said the State Department’s regional security officer in Tripoli, Libya, had reported that the mission in Benghazi was under attack, and that “20 armed people fired shots.”

An email 49 minutes later said the firing at the consulate “has stopped and the compound has been cleared,” while a response team was trying to find people. In the next message, 1 hour 13 minutes after the second, the embassy in Tripoli reported that a local militant group, Ansar al-Shariah, had claimed responsibility for the attack through postings on Facebook and Twitter.

In the hours after the Benghazi attack, which killed Ambassador J. Christopher Stevens and three other Americans at the mission in Benghazi on Sept. 11, U.S. spy agencies intercepted electronic communications from Ansar al-Shariah fighters bragging to an operative with al-Qaida in the Islamic Maghreb, the group’s North African affiliate. But Ansar al-Shariah has publicly denied involvement in the attack.

A White House spokesman, Jay Carney, traveling with President Obama on Air Force One, said the emails, reported by Reuters, were unclassified and among “all sorts of information that was becoming available in the aftermath of the attack.”

Some Republicans have criticized the U.S. ambassador to the United Nations, Susan Rice, for stating five days after the attack that it had resulted from a spontaneous mob that was angry about an anti-Islamic video, even though some intelligence reports and eyewitness accounts indicated a terrorist attack. Rice said she had based her comments on unclassified talking points prepared by the CIA.

The issue seemed to die down after Mitt Romney did not press Obama on the matter in their debate Monday.

On Wednesday, three Republican senators, John McCain of Arizona, Lindsey Graham of South Carolina and Kelly Ayotte of New Hampshire, criticized Obama in a letter, saying the series of emails “only adds to the confusion surrounding what you and your administration knew about the attacks in Benghazi, when you knew it, and why you responded to those tragic events in the ways you did.”

Intelligence officials say the gap between the talking points and the contemporaneous field reports illustrates the lag between turning often contradictory and incomplete field reporting into a finished assessment.

Administration and intelligence officials made that point again Wednesday in trying to put into context the emails sent by the State Department operations center to scores of officials at the Pentagon, State Department and White House.

“You know, posting something on Facebook is not in and of itself evidence, and I think it just underscores how fluid the reporting was at the time and continued some time to be,” Secretary of State Hillary Rodham Clinton told reporters at the State Department.