NEW YORK -- Secretary of State Hillary Clinton on Wednesday tied the attack that killed the U.S. ambassador to Libya to the creation of an al Qaida haven in Mali, adding that Islamist militants there pose a threat to democratic transitions throughout northern Africa.

Clinton’s remarks on the sidelines of this week’s U.N. General Assembly suggest that the White House is revising its first account that the attack on the U.S. consulate in Benghazi, which killed Ambassador Christopher Stevens and three other Americans, was the result of spontaneous mob violence.

Libyan officials for days have said that evidence at the scene points to a more organized militant operation, perhaps stemming from the Maghreb or Sahel regions of North Africa, where an al Qaida branch is active. Clinton edged closer to that view Wednesday without outlining any evidence and stopping just short of making a direct link.

“For some time, al Qaida in the Islamic Maghreb and other groups have launched attacks and kidnappings from northern Mali into neighboring countries,” Clinton told leaders at a U.N. meeting on North Africa’s political and security crises.

“Now, with a larger safe haven and increased freedom to maneuver, terrorists are seeking to extend their reach and their networks in multiple directions,” she continued, “and they are working with other violent extremists to undermine the democratic transitions underway in North Africa, as we tragically saw in Benghazi.”

A senior State Department official, who briefed reporters on the condition of anonymity, cautioned that Clinton was not saying that al Qaida in the Maghreb was behind the Benghazi attack, only that it was a growing threat to the region.

"With regard to the specific issue of who was responsible for the Benghazi attack, as everybody in the administration has said, we can’t go beyond our preliminary statements until we have the results of the FBI investigation," the official said.

In Washington, the administration’s initial hesitation to say that Stevens and the other three Americans died in a “terrorist attack” continued to roil the political waters.

“We are . . . disturbed by the public statements by members of the administration that would lead the American public to believe this attack was a protest gone wrong, rather than what it truly was – a terrorist attack on the United States on the anniversary of 9/11,” the Republican chairmen of eight House committees wrote to President Barack Obama.

They called on Obama to provide Congress with more information on the incident, saying that many questions “were left unanswered” by a closed-door briefing they received last week from Clinton and other senior officials.

The administration initially said that the attack was unplanned and grew out of a protest at the consulate that was inspired by a demonstration in front of the U.S. Embassy in Cairo against a cheap online video denigrating Islam’s Prophet Muhammad.

But the president of Libya’s interim government, Mohammad Magarief, has said publicly that the attack was organized and planned in advance by foreigners, some linked to al Qaida, carried out by local extremists and deliberately timed for the anniversary of the Sept. 11, 2001 attacks on the United States. Witnesses also described the assault to McClatchy as well-organized and denied that a protest was going on at the time.