TRIPOLI, Libya >> Libyan rebels moved into the capital Tripoli today and came within two miles of the city center, as Moammar Gadhafi’s defenders melted away. The rebel leadership 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. 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.

One of the rebels, Mohammed al-Zawi, 30, said he was in a convoy of more than 10 trucks that entered Ghot Shaal. He said they progressed as far as the neighborhood of Girgash, about a mile and a half from Green Square, where Gadhafi supporters have gathered nightly throughout the uprising to rally for their leader of more than 40 years.

He said the rebels came under fire from a sniper on a rooftop in the neighborhood.

“They will enter Green Square tonight, God willing,” al-Zawi said.

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.

The trappings of  Gadhafi’s regime were crumbling fast, with opposition forces rising up from within his stronghold at the same time.

The rebels reached the Tripoli suburb of Janzour around nightfall today. They were greeted by civilians lining the streets and waving rebel flags. Hours earlier, the same rebel force of hundreds drove out elite forces led by Gadhafi’s son Khamis in a brief gunbattle.

The elated fighters danced and cheered, hauling off truckloads of weapons and advanced full speed toward the capital in pickup trucks. Ahmed al-Ajdal, 27, a fighter from Tripoli, was loading up a truck with ammunition.

“This is the wealth of the Libyan people that he was using against us,” he said, pointing to his haul. “Now we will use it against him and any other dictator who goes against the Libyan people.”

Inside Tripoli, there was a second day of widespread clashes between what the opposition called “sleeping cells” of rebels who are rising up and Gadhafi loyalists. There were also large anti-government protests.

Libyan state television aired an audio message from Gadhafi tonight, his second in less than 24-hours. He sounded angry and urged 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. He sounded like he was speaking on a phone line.

An AP reporter with the rebels rapidly advancing toward Tripoli saw them take over the base of the Khamis Brigade, 16 miles west of Tripoli. After a brief gunbattle, Gadhafi’s forces fled what was once a major symbol of the regime’s power.

Gadhafi’s 27-year-old son Khamis commands the 32nd Brigade, also known simply as the Khamis Brigade, one of the best trained and equipped units in the Libyan military.

Inside the base, hundreds of rebels cheered wildly and danced, raising the rebel flag on the front gate of a large, gray wall enclosing the compound. They seized large stores of weapons, driving away with truckloads of whatever arms they could get their hands on. One of the rebels carried off a tube of grenades, while another carted off two mortars.

Mahmoud al-Ghwei, 20 and unarmed, said he had just came along with a friend for the ride into Tripoli with the advancing force.

“It’s a great feeling. For all these years, we wanted freedom and Gadhafi kept it from us. Now we’re going to get rid of Gadhafi and get our freedom,” he said.

Inside the large, open compound filled with eucalyptus trees were three gigantic wooden crates labeled “Libyan Armed Forces.” They were loaded with large-caliber ammunition for anti-aircraft guns.

The rebels were busy loading two huge trucks with boxes full of ammunition. One carried armfuls of RPGs.

They were chanting: “We are coming for you, frizz-head.”

The rebels said they freed 300-400 prisoners detained on the base. An AP reporter saw some cars coming back west from the front with dozens of the freed prisoners, dressed in tattered T-shirts, prison uniforms and barefoot.

One of the freed prisoners, 23-year-old Majid al-Hodeiri from nearby Zawiya, said he was captured four months ago by Gadhafi’s forces and taken to base. He said he was beaten and tortured while under detention

“We were sitting in our cells when all of a sudden we heard lots of gunfire and people yelling ‘Allahu Akbar.’ We didn’t know what was happening, and then we saw rebels running in and saying ‘We’re on your side.’ And they let us out,” he said.

Rebels said Saturday that they had launched their first attack on Tripoli in coordination with NATO and gunbattles and mortar rounds rocked the city. NATO aircraft also made heavier than usual bombing runs after nightfall, with loud explosions booming across the city.

Today, more heavy machine gun fire and explosions rang out across the capital with more clashes and protests.

Government minders in a hotel where foreign journalists have been staying in Tripoli have begun to arm themselves with weapons in anticipation of a rebel take over. The hotel manager said he had received calls from angry rebels threatening to charge the hotel to capture the government’s spokesman, Moussa Ibrahim.

Heavy gun fire was heard in the neighborhood around the Rixos hotel, and smoke was seen rising from a close by building.

“We are scared and staying in our houses, but the younger boys are going out to protect our homes,” said a woman who spoke to The Associated Press by telephone from the pro-rebel Tripoli neighborhood of Bin Ashour. She spoke on condition of anonymity for fear of reprisal. She said a neighbor’s son was shot dead on Saturday night by Gadhafi troops as he tried to protect his street with a group of rebel youth.

Nuri al-Zawi, another resident of Bin Ashour, told the AP by phone that the rebels were using light arms to protect their streets, and in some cases were using only their bodies to fend off the Gadhafi troops riding in pickup trucks.

“We are used to this situation now. We are a city that is cut off from the world now,” he said.

The residents reported clashes in neighborhoods all over Tripoli as well as the city’s Mitiga military airport. They said they heard loud explosions and exchanges in of gunfire in the Fashloum, Tajoura and Bin Ashour neighborhoods. Residents and opposition fighters also reported large anti-regime protests in those same neighborhoods. In some of them, thousands braved the bullets of snipers perched atop high buildings.

Mukhtar Lahab, a rebel commander closing in on Tripoli and a former captain in Gadhafi’s army, said his relatives inside the capital reported mass protests in four neighborhoods known as sympathetic to the opposition: Fashloum, Souk al-Jouma, Tajoura and Janzour. He said mosques there were rallying residents with chants of “Allahu Akbar” or “God is great,” broadcast on loudspeakers.

At the same time, hundreds of rebels in pickup trucks and even some on foot were moving full speed toward the capital from the west. It was those rebels who captured the Khamis Brigade base.

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.”

Rebel Murad Dabdoub told the AP that Gadhafi’s forces were pounding rebel positions west of the city with rockets, mortars and anti-aircraft fire.

“We are not going back. said Issam Wallani, another rebel. “God willing, this evening we will enter Tripoli.”