Qaddafi: "This is the zero hour"

In a new audio message from hiding, Muammar Qaddafi called on his followers to rise up and fight, saying "this is the zero hour."

Fighters from the revolutionary forces that drove him from power last month have begun an assault on the town of Bani Walid, one of one of the last remaining areas still under control of Qaddafi.

"Shame on you if you don't fight. If you don't fight, you will go to hell," he said in a message that was repeatedly broadcast on a Bani Walid radio station Saturday night.

Witnesses reported earlier Saturday seeing multiple NATO airstrikes on the town, southeast of Tripoli. But while NATO confirmed to Reuters that it was conducting air sorties over the city, it would not discuss operations there.

Meanwhile, the chief of Libya's former rebels, Mustafa Abdul-Jalil, arrived in Tripoli on Saturday, greeted in a boisterous red carpet welcome meant to show he's taking charge of the interim government replacing the ousted regime of Qaddafi.

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Loyalists of Muammar Qaddafi, holed up in one his remaining strongholds, attacked Libyan fighters with mortar rounds and sniper fire Saturday, a sign of the difficulties former rebels face in taking full control of the vast country.

After the fall of Tripoli, revolutionary forces chased retreating Qaddafi loyalists into three bastions of support for the former regime, including Bani Walid, Qaddafi's hometown of Sirte and the southern town of Sabha. However, it has proven difficult for the anti-Qaddafi troops to capture the three towns, suggesting that the former dictator still commands some support. The fugitive Qaddafi has said he won't surrender and has exhorted his followers to keep fighting.

Revolutionary forces and regime loyalists had been engaged in off-and-on surrender talks in Bani Walid, a town some 90 miles (140 kilometers) southeast of Tripoli, for more than a week. Fighting erupted on Friday and escalated Saturday.

After midday Saturday, anti-Qaddafi fighters in a desert valley some two miles from Bani Walid came under heavy attack from loyalists. Loud explosions were heard as mortar rounds struck the area, releasing clouds of dust and smoke. Snipers also targeted rebel fighters, as ambulances sped up and down the main road into town.

Some said disagreements broke out over which group of fighters should lead the assault on Bani Walid. The town is a base of the Warfala tribe, one of Libya's largest.

Bassam Turki, 33, a fighter from Tripoli, said he was told by comrades from Bani Walid that they wanted to drive out the Qaddafi loyalists without the help of forces from other towns. "If Bani Walid (fighters) could liberate the city without our help, why didn't they do this a long time ago?" he said angrily.

At least two anti-Qaddafi fighters were killed, said Abdullah Kanshil, a negotiator with the former rebels. The commander of the assault, Daw Salaheen, called on the city's residents to lay down their arms, saying anyone who does so will be "safe in our hands."

Volunteers asking to join the battle said Saturday they were getting increasingly impatient with the standoff. Dozens crowded around a desk at a mosque in Wishtata, a hamlet about 25 miles from Bani Walid, to register their names, blood type and other information.

Abdel Wahab Milad, a 26-year-old teacher from the town of Gharyan, drove dozens of miles to the front in a pickup truck with six friends. Dressed in army fatigues, he said he signed up for battle because it was time to "get rid of Qaddafi once and for all."

On Friday, revolutionary forces also battled loyalists near the Qaddafi hometown of Sirte, 250 miles southeast of Tripoli, but withdrew after heavy casualties.

Meanwhile, officials in neighboring Niger said four senior Libyan military officers have entered the country.

Justice Minister Amadou Morou said late Friday that the Libyan chief of staff of the air force, his pilot and the commanders of two Libyan military regions have arrived in Niger. Morou declined to name the officers.

Morou condemned an attempted attack on the Embassy of Niger in Tripoli on Wednesday night by a group of 20 armed men who tried to force their way in. He said the compound is now being offered protection by Libya's National Transitional Council, the political leadership of the former rebels and the closest thing Libya has to a government.

Libya's new rulers had set a Saturday deadline for Qaddafi loyalists in Bani Walid, Sirte, and Sabha, deep in Libya's southern desert, to surrender or face an offensive.

Mustafa Abdul-Jalil, head of the anti-Qaddafi forces' National Transitional Council, landed Saturday at an air force base on the outskirts of Tripoli. A tattered red carpet was rolled out, and hundreds of fighters and officials in suits rushed toward the plane as he walked down the steps. Some flashed victory signs or shouted "God is great."

Abdul-Jalil was mobbed by the crowd as he tried to make his way to the air force building. At one point, a fistfight broke out between two guards. One of the guards waved a pistol in the air and was knocked down by bystanders using a metal detector and a potted plant, before Abdul-Jalil was rushed into a secure area.

Despite the chaos, no shots were fired.

Abdul-Jalil's arrival was meant to show that the former rebels are getting ready to establish their government in the capital. Until now, most of leaders of the anti-Qaddafi movement had been based in the eastern city of Benghazi.

The leader's presence "means that Tripoli is safe and that we can look to the future," said Atia al-Mansouri, a former air force pilot who was among those waiting on the tarmac.

Revolutionary forces entered Tripoli on Aug. 21, six months after the uprising against Qaddafi began.

The fall of Tripoli effectively sealed the fate of Qaddafi's regime, but Abdul-Jalil stayed away from the capital until Saturday. His absence had at times raised questions about the former rebels' ability to take charge.

Officials close to Abdul-Jalil cited security concerns as one of the reasons for his prolonged absence.

While anti-Qaddafi forces have driven armed loyalists out of Tripoli, the security situation remains shaky. The capital has been flooded with weapons, including those in the hands of civilians.

Earlier Saturday, as reporters waited for Abdul-Jalil's arrival at the air force base, a group of fighters escorted a wooden coffin to a nearby plane. The coffin carried a fighter who was killed Friday by a young civilian in Tripoli's main square. The assailant drew a pistol and shot the fighter in the chest, after being told he could not enter the square, said Rafa al-Mogherbi, a fighter who witnessed the shooting.