AJDABIYA, Libya – Libyan rebels clinched their hold on the east and reclaimed a key city Saturday after decisive international airstrikes sent Moammar Gadhafi’s forces into retreat, shedding their uniforms and ammunition as they fled.

Ajdabiya’s initial loss to Gadhafi may have ultimately been what saved the rebels from imminent defeat, propelling the U.S. and its allies to swiftly pull together the air campaign now crippling Gadhafi’s military. Its recapture gives President Obama a tangible victory just as he faces criticism for bringing the United States into yet another war.

In Ajdabiya, drivers honked in celebration and flew the tricolor rebel flag. Others in the city fired guns into the air and danced on burned-out tanks that littered the road.

Their hold on the east secure again, the rebels promised to resume the march westward that had been reversed by Gadhafi’s overwhelming firepower. Rebel fighters already had pushed forward to the outskirts of the oil port of Brega and were hoping to retake the city today, opposition spokeswoman Iman Bughaigis said, citing rebel military commanders.

“Without the planes we couldn’t have done this. Gadhafi’s weapons are at a different level than ours,” said Ahmed Faraj, 38, a rebel fighter from Ajdabiya. “With the help of the planes we are going to push onward to Tripoli, God willing.”

The Gadhafi regime acknowledged the airstrikes had forced its troops to retreat and accused international forces of choosing sides.

“This is the objective of the coalition now. It is not to protect civilians because now they are directly fighting against the armed forces,” said Khaled Kaim, the deputy foreign minister. “They are trying to push the country to the brink of a civil war.”

Ajdabiya’s sudden capture by Gadhafi’s troops March 15 — and their move toward the rebel capital of Benghazi — gave impetus to the U.N. resolution authorizing international action in Libya, and its return to rebel hands Saturday came after a week of airstrikes and missiles against the Libyan leader’s military.

Airstrikes Friday on the city’s eastern and western gates forced Gadhafi’s troops into hasty retreat. Inside a building that had served as their makeshift barracks and storage, hastily discarded uniforms were piled in the bathroom and books on Islamic and Greek history and fake pink flowers were scattered on the floor.

Saif Sadawi, 20, a rebel fighter with a rocket-propelled grenade launcher in his hands, said the city’s eastern gate fell late Friday and the western gate fell at dawn Saturday after airstrikes on both locations.

“All of Ajdabiya is free,” he said.

Rebels swept into the city and hauled away a captured rocket launcher and a dozen boxes of anti-aircraft ammunition, adding to their limited firepower. Later in the day, other rebels drove around and around a traffic circle, jubilantly firing an assortment of weapons in the air — anti-aircraft weapons, AK-47s, RPGs.

Outside the city, Muftah el-Zewi was driving away, his back seat loaded with plastic bags filled with blankets and clothes that he picked up after going to his home in Ajdabiya for the first time in days.

“We went and checked it out, drove around the neighborhood and it looked OK. Hopefully we’ll come back to stay tomorrow,” he said.

The turnaround is a boost for Obama, who has faced complaints from lawmakers from both parties that he has not sought their input about the U.S. role in the conflict or explained with enough clarity about the American goals and exit strategy. Obama was expected to give a speech to the nation Monday.

“We’re succeeding in our mission,” the president said in a radio and Internet address. “So make no mistake, because we acted quickly, a humanitarian catastrophe has been avoided and the lives of countless civilians — innocent men, women and children — have been saved.”

The U.N. Security Council authorized the operation to protect Libyan civilians after Gadhafi launched attacks on anti-government protesters who demanded that the Libyan leader step down after 42 years in power.

The airstrikes have crippled Gadhafi’s forces, but rebel advances have also foundered, and the sides have been at stalemate in key cities.