ZAWIYA, Libya -- Moammar Gadhafi's forces pushed rebels back from the center of the strategic city of Zawiya on Monday in fierce fighting to try to prevent the opposition from consolidating a major advance to within 30 miles of the capital Tripoli.
In neighboring Egypt, Libyan Interior Minister Nassr al-Mabrouk Abdullah flew into the capital Cairo on his private plane with nine family members, Egyptian airport officials said. He came from Tunisia and entered on a tourist visa in what could be a high-level defection. No Libyan embassy officials greeted him at the airport.
"We had no idea of his arrival, but he was in Tunisia on Sunday," a Libyan embassy official in Cairo told The Associated Press. All officials spoke on condition of anonymity because they weren't authorized to speak to the media. The Libyan embassy official confirmed that Abdullah is the interior minister.
The minister arrived after a weekend of significant advances by rebels from Libya's western mountains toward Gadhafi's stronghold of Tripoli. The rebels on Saturday pushed through to Zawiya, just 30 miles (48 kilometers) west of the capital on the Mediterranean coast, for the first time since the uprising against Gadhafi began in February.
The rebel advance was raising fears among Tripoli residents over the prospect that fighting might soon reach the capital. Cars carrying civilians fleeing Tripoli crossed checkpoints on a desert road around Zawiya, headed for the rebel-held western mountains.
"We are afraid of whatever is coming," said Mohammed Bilkheir, an accountant escaping Tripoli with his family. He said he was leaving to stay with relatives in the western mountains, fearing battles would break out in Tripoli.
On Monday, regime forces pushed the rebels back from the center of Zawiya in fighting concentrated on the main coastal road connecting Tripoli and the border crossing with Tunisia. Armed pickup trucks dashed to and from Zawiya's city center on Ghanam Street, where the battles have raged over the past four days.
Rebels in Zawiya were running low on ammunition. Some sat huddled on the sides of streets, taking cover by the walls of buildings as they waited for more supplies to arrive.
On Sunday, the rebels said they were trying to cut off two of Gadhafi's crucial overland supply routes, critical with NATO imposing a no-fly zone over the country.
They claimed to have captured at least two other towns near Tripoli that sit on key supply routes for the capital. They said they now held the town of Gharyan, 50 miles (80 kilometers) south of Tripoli.
The capture of Zawiya, which is home to the government's only functioning oil refinery, would mark a significant gain for rebels in the west.
Omar Obeid, field commander for the Sabratha area, 20 miles (32 kilometers) west of Zawiya on the coast, said late Sunday that rebels had taken up positions in houses along a major supply route there that connects the Ras Ajdir border crossing with Tunisia to Tripoli. The same road runs through Zawiya, where rebels could also block it if they manage to take control of the city.
Rebels said they also captured the town of Surman, near Sabratha to the southeast.
But the rebels' gains could easily be reversed by Gadhafi's better trained and equipped troops.