ZAWIYA, Libya -- Libyan rebels expelled government forces from the strategic western city of Zawiya on Saturday, a major victory for the opposition in their march on Moammar Gadhafi's stronghold of Tripoli.
The territory remaining under the Libyan ruler's control has been shrinking dramatically in the past three weeks, with opposition fighters advancing on the capital, a metropolis of 2 million people, from the west, south and east.
The biggest prize so far in the rebels' three-week-old offensive is Zawiya, a coastal city just 30 miles (50 kilometers) west of Tripoli. They also claim to have captured two more towns -- Zlitan in the west and Brega in the east.
The momentum in the six-month-old Libyan civil war now appears to have firmly swung in the rebels favor after months of near deadlock.
Besides the battlefield gains, the opposition also received a political boost Friday with the defection of Abdel-Salam Jalloud, a close associate of Gadhafi who took part in the 1969 coup that brought the Libyan ruler to power.
On Saturday, rebel fighters and pickup trucks poured into Zawiya's main square. Signs of the fierce fighting over the past week were all around: The pockmarked and shattered facades of buildings ringing the plaza, the bodies of two Gadhafi soldiers lying on the ground.
For more than a week, fighting in Zawiya focused on two main streets -- Omar Mokhtar and Gamal Abdel-Nasser streets -- with Gadhafi snipers positioned on top of a hospital, bank and hotel overlooking the main square.
Government forces appeared to have fled those strategic positions and others in the eastern half of the city they still held on Friday.
An Associated Press reporter visited those positions -- all of which are now under rebel control. In the distance, the rumble of shelling could be heard to the east.
At the Zawiya hospital, rebel fighter Mohammed Abu Dayyah said that 150 rebels attacked the hospital from two sides on Friday, overcoming what little resistance Gadhafi's forces offered.
"Mortar shells hit the hospital at one o'clock this morning and destroyed the operating theaters," he said.
Wires dangled from the ceiling of the destroyed operating rooms. Doctors had quickly set up the dialysis room where a dozen patients received treatment.
Ambulances ferrying doctors from outside Zawiya sped to the hospital to start taking charge of the operations there. The doctors jumped out of the vehicle celebrating with cries of "God is great."
The main square in Zawiya was littered empty ammunition casings. The windows of the seven-story hotel once occupied by Gadhafi troops were blown out and scorch marks from shelling marked its peach-colored facade.
Outside Zawiya, dozens of cars rushed through rebel checkpoints carrying families fleeing Tripoli. Their cars piled high with mattresses and supplies, those fleeing told of tense capital where Gadhafi loyalists were digging in.
"The situation is tragic in Tripoli, there is security everywhere but no electricity or gas," said Rabie Salem, who fled the capital Saturday. "The people are living in fear and no one will go out and demonstrate."
Salem said she and her family tried to leave the capital Friday but were turned back by Gadhafi forces at a checkpoint. She said they managed to escape Saturday by traveling on back roads.
Gadhafi loyalists have begun blocking off streets with concrete barriers and thrown up more checkpoints, she said. The forces looked like they were preparing for battle as they positioned more soldiers on rooftops.
As Zawiya fell to the rebels in the west, opposition fighters elsewhere also reported major advances.
In the east, rebels said they have captured all of the strategic eastern port city of Brega, which has repeatedly changed hands in the 6-month-old civil war.
Brega is home to Libya's second-largest hydrocarbon complex and is where the country's main oil fields feed into for refining.
In the west, rebels also claimed to have taken control of Zlitan, 90 miles (140 kilometers) southeast of Tripoli.
In the United Kingdom, Major General Nick Pope, the Chief of the Defense Staff's Communications Officer, said that RAF planes as part of NATO's mission in Libya had attacked two staging areas used by Gadhafi forces in Zlitan.
He told reporters Saturday that RAF aircraft returned to Tripoli on Friday evening and bombed the main operations room for the Ministry of Interior's security forces, which NATO intelligence had identified as located in a compound in the Abu Salim district.
Hundreds of miles east of Libya, Assistant Secretary of State Jeffrey Feltman visited the rebels' de-facto capital of Benghazi to announce the opening of the U.S. Embassy in the city.
"Gadhafi's days are numbered," Feltman told reporters on Saturday. "The best case scenario is for Gadhafi to step down now... that's the best protection for civilians."