One rebel said that after their initial defeat, opposition forces destroyed armored vehicles and captured dozens of fighters from Gadhafi's elite Khamis Brigade in the oil town of Brega, driving others back into the town's airport.

Another opposition fighter told The Associated Press by telephone that celebrations had broken out in the nearby city of Ajdabiya, and celebratory gunfire, honking and shouting could be heard in the background.

"We are on our way to Brega to celebrate with our brothers there," he said.

The opposition has seen a series of reversals in its battle for control of Libya's main coastal highway, which runs from Gadhafi's western stronghold in the capital, Tripoli, to rebel-held territory in the east. Gadhafi's forces seem emboldened by their string of victories but their supply lines are increasingly stretched and they depend on artillery, airstrikes and naval attacks that are more difficult to launch at night.

The rebels have been pleading for Western powers to protect them with a no-fly zone, and on Monday their leaders meet in Paris with U.S. Secretary of State Hilary Rodham Clinton, who plans to assess their capabilities and intentions.