President Obama briefed on Tripoli fighting

A vacationing President Barack Obama was being given updates every few hours on developments in Libya. U.S. officials were reportedly in touch with government contacts in Libya Saturday to determine the progress of rebel troops advancing on Libya's capital, Tripoli.

A senior administration official said the president was briefed during the day on Martha's Vineyard, Mass., and would continue to get regular updates, including through the night if necessary. A second senior official said the administration was in close contact with the Libyan opposition and U.S. allies and partners, and believes that Muammar Gaddafi's days in power are numbered, the AP reported

Analysts have concluded that Gaddafi's unpredictable decision-making style means he could decide within hours to flee, or stay to the bitter end.

U.S. officials say they were monitoring the situation closely, without specifying the U.S. role in the NATO bombing, ABC reported.

Reporters in Tripoli heard gunfire and explosions after rebel troops seized control of Zawiya, a major coastal city not far from the capital. Rebel leaders called it the start of an attack on Gaddafi's main stronghold.

"We planned this operation with NATO, our Arab associates and our rebel fighters in Tripoli with commanders in Benghazi," Mustafa Abdel-Jalil, the head of the rebel leadership council, told the Arab satellite channel Al-Jazeera.

U.S. Assistant Secretary of State Jeffrey Feltman visited the rebel headquarters in the city of Benghazi, and announced the reopening of Libya's embassy in Washington, D.C., under the control of the opposition Transitional National Council, not Gaddafi's envoys, ABC reported.

The Obama administration approved the embassy's reopening in August after formally recognizing the Benghazi-based Council as Libya's governing body.

The State Department shut down the Libyan Embassy in February after closing the U.S. Embassy in Tripoli.

"Gaddafi's days are numbered," Feltman told reporters in Benghazi Saturday. "The best-case scenario is for Gaddafi to step down now … that's the best protection for civilians."