BANI WALID, Libya -- Moammar Gadhafi's fighters fired several mortars and tried to ambush revolutionary forces Sunday at the northern gate of the loyalist stronghold of Bani Walid. With their numbers stretched thin, the former rebels sent reinforcements, some who arrived with a tank that had been seized from the ousted regime.
Libya's new rulers, meanwhile, pressed forward with efforts to assert authority over the country. The National Transitional Council planned a press conference later Sunday to announce a new Cabinet lineup. That would show progress in forming a new government ahead of the U.N. General Assembly this week.
The two sides have clashed for days after former rebels made a push toward Bani Walid and Gadhafi's hometown of Sirte to try to break weeks of stalemate and crush the dug-in fighters loyal to the fugitive leader.
While Sirte would be a major symbolic prize, Bani Walid has proven particularly difficult for revolutionary forces.
The loyalists hold the strategic high ground along the ridges overlooking a desert valley called Wadi Zeitoun that divides the town between northern and southern sections. The terrain has made the city a historical hold-out: In the early 20th century, Italian forces occupying Libya struggled to take Bani Walid.
On Sunday, Gadhafi forces blasted fighters at the northern entrance with mortar fire while the revolutionary forces returned fire with machine guns and rocket-propelled grenades. Fighters also fired into the desert north of the gate where Gadhafi loyalists were believed to be trying to surround them ahead of an ambush.
Five mortar shells landed about 20 yards (meters) from a building where anti-Gadhafi fighters were resting, prompting them to run to a feed factory they have occupied. Black smoke filled the sky.
The standoff has been chipping away at the morale of fighters, who have been massed in the area for weeks and are stretched thin. While the northern gate was coming under attack, many sat on the sidelines drinking tea and using plastic bottles for target practice at the feed factory checkpoint.
The reinforcements from Tajoura, meanwhile, posed on a tank they said had been captured after revolutionary forces swept into Tripoli on Aug. 21. Fathi Mselati, 31, from the Tajoura brigade, said more captured tanks were on their way to the front.
Revolutionary forces also have faced fierce resistance in Sirte as they tried to push through crowded residential areas in the coastal city, but they claimed Saturday to have gained less than a mile into the city, along the main coastal highway leading in from the west.
The forces were met by a rain of gunfire, rockets and mortars. A field hospital set up outside Sirte at a gas station filled with wounded fighters, including some from a convoy hit by a rocket-propelled grenade. Twenty-four anti-Gadhafi fighters were killed and 54 wounded in the day's battles, the military council from the nearby city of Misrata reported.
The pro-regime radio station in Sirte repeatedly aired a recorded message it said was from Gadhafi, urging the city's defenders to fight on. "You must resist fiercely. You must kick them out of Sirte," the voice said. "If they get inside Sirte, they are going to rape the women." The voice resembled Gadhafi's but its authenticity could not be confirmed.
Gadhafi's spokesman, Moussa Ibrahim, vowed, "We have the ability to continue this resistance for months," in a phone call Friday to Syrian-based Al-Rai TV, which has become the mouthpiece for the former regime.
The persistence of the former regime has raised fears of a protracted insurgency of the sort that has played out in Iraq and Afghanistan.
Hassan Dourai, Sirte representative in the new, interim government, said fighters reported seeing one of Gadhafi's sons, Muatassim, shortly before the offensives began Friday, but he has not been spotted since the battles intensified. The whereabouts of Gadhafi and several of his sons remain unknown. Other family members have fled to neighboring Algeria and Niger.
On a third front in Libya's southern desert, hundreds of revolutionary fighters were negotiating with villagers in the still pro-Gadhafi region to surrender peacefully. The fighters collected on a road near the Nahrouqa village on Sunday.
Col. Bashir Awidat has said they seek to secure the surrounding hinterlands before moving against Sabha, the main southern urban center about 400 miles (650 kilometers) south of Tripoli.
Associated Press writer Ryan Lucas in Sirte contributed to this report.