TRIPOLI, Libya — Euphoric Libyan rebels moved into the capital Tripoli on Sunday and moved close to center with little resistance as Moammar Gadhafi's defenders melted away. The opposition's leaders said Gadhafi's son and one-time heir apparent, Seif al-Islam, has been arrested.
Associated Press reporters with the rebels said they met little resistance as they moved from the western outskirts into the capital in a dramatic turning of the tides in the 6-month-old Libyan civil war.
"They will enter Green Square tonight, God willing," said Mohammed al-Zawi, a 30-year-old rebel in the force that was moving in. Green Square has been the site of night rallies by Gadhafi supporters throughout the uprising.
Gadhafi's regime appeared to be rapidly crumbling.
Earlier in the day, the rebels overran a major military base defending the capital, carted away truckloads of weapons and raced to Tripoli with virtually no resistance.
The rebels' surprising and speedy leap forward, after six months of largely deadlocked civil war, was packed into just a few dramatic hours. By nightfall, they had advanced more than 20 miles to Gadhafi's stronghold.
Along the way, they freed several hundred prisoners from a regime lockup. The fighters and the prisoners — many looking weak and dazed and showing scars and bruises from beatings — embraced and wept with joy.
Thousands of jubilant civilians rushed out of their homes to cheer the long convoys of pickup trucks packed with rebel fighters shooting in the air. Some were hoarse, shouting: "We are coming for you, frizz-head," a mocking nickname for Gadhafi. In villages along the way that fell to the rebels one after another, mosque loudspeakers blared "Allahu Akbar," or "God is great."
"We are going to sacrifice our lives for freedom," said Nabil al-Ghowail, a 30-year-old dentist holding a rifle in the streets of Janzour, a suburb just six miles west of Tripoli. Heavy gunfire erupted nearby.
As town after town fell and Gadhafi forces melted away, the mood turned euphoric. Some shouted: "We are getting to Tripoli tonight." Others were shooting in the air, honking horns and yelling "Allahu Akbar."
Once they reached Tripoli, the rebels took control of one neighborhood, Ghot Shaal, on the western edge of the city. They set up checkpoints as rebel trucks rolled into Tripoli. A convoy of more than 10 trucks entered Ghot Shaal.
The rebels moved on to the neighborhood of Girgash, about a mile and a half from Green Square. They said they came under fire from a sniper on a rooftop in the neighborhood.
Sidiq al-Kibir, the rebel leadership council's representative for the capital Tripoli, confirmed the arrest of Seif al-Islam to the AP but did not give any further details.
Inside Tripoli, widespread clashes erupted for a second day between rebel "sleeper cells" and Gadhafi loyalists. Rebels fighter who spoke to relatives in Tripoli by phone said hundreds rushed into the streets in anti-regime protests in several neighborhoods.
Libyan state television aired an angry audio message from Gadhafi Sunday night, urging families in Tripoli to arm themselves and fight for the capital.
"The time is now to fight for your politics, your oil, your land," he said. "I am with you in Tripoli — together until the ends of the earth," Gadhafi shouted.
The day's first breakthrough came when hundreds of rebels fought their way into a major symbol of the Gadhafi regime — the base of the elite 32nd Brigade commanded by Gadhafi's son, Khamis. Fighters said they met with little resistance.
Hundreds of rebels cheered wildly and danced as they took over the compound filled with eucalyptus trees, raising their tricolor from the front gate and tearing down a large billboard of Gadhafi.
Inside, they cracked open wooden crates labeled "Libyan Armed Forces" and loaded their trucks with huge quantities of munitions. One of the rebels carried off a tube of grenades, while another carted off two mortars.
"This is the wealth of the Libyan people that he was using against us," said Ahmed al-Ajdal, 27, pointing to his haul. "Now we will use it against him and any other dictator who goes against the Libyan people."
One group started up a tank, drove it out of the gate, crushing the median of the main highway and driving off toward Tripoli. Rebels celebrated the capture with deafening amounts of celebratory gunfire, filling the air with