BENGHAZI, Libya — After fierce battles in desert towns and oases, revolutionary forces now control most of Libya's vast south, making it harder for Moammar Gadhafi's loyalists to flee into neighboring Niger, Chad and Algeria, southern representatives to the interim ruling authority said Thursday.
They said 18 revolutionary fighters died in the final battle for the deep south's largest city, Sabha, and that pro-Gadhafi resistance consisted now of what they called a few last pockets of holdouts.
A CNN crew traveling with the former rebels discovered a warehouse near Sabha that contained thousands of barrels of yellowcake uranium, which can be refined for use in nuclear weaponry.
United Nations atomic energy monitors said the Gadhafi regime had declared the site previously and it had been inventoried. Ensuring that the site is secure now falls to Libya's interim authorities until the area is stable enough for inspectors to visit, said Gill Tudor, a spokeswoman for the International Atomic Energy Agency in Vienna.
Even as the revolutionaries declared victory in the south, they were unable to overcome fierce resistance at two Gadhafi loyalist strongholds farther north.
Revolutionary forces attempting to seize the desert town of Bani Walid and Gadhafi's hometown of Sirte on the Mediterranean coast found their advances stalled by rough terrain, poor supply lines and the fact that Gadhafi brigades that were routed from other areas are now concentrated in the two cities.
Seizing Bani Walid and Sirte would allow the revolutionary forces to declare their control over all of Libya, paving the way for the declaration of a formal caretaker government to fill the power vacuum left by the Gadhafi regime's collapse.
Col. Ahmed Bani, the military spokesman for revolutionary forces, said that at least 18 revolutionaries fighting in Sirte were killed in the past few days. He said commanders had reported that some of the men had been chained to trucks and dragged on the ground until they were dead. Bani said anti-Gadhafi forces were about 10 miles from the city center.
The former rebels are "controlling the military air base and the airport, but there's still resistance," Bani said by telephone from Tripoli. "Sooner or later, we'll take it."
In Bani Walid, he said, progress has been slow because of sniper nests in the mountains overlooking a main approach to the city. Gadhafi's forces also had poured petroleum and a lubricant used in oil refineries on roads into the city, he said. The former rebels' vehicles can get no traction, leaving them at risk of being pinned under sniper fire with their wheels spinning if they attempt to enter. He said the forces were looking at alternative routes.
In response to reports that the former rebels were running low on ammunition and suffered from a lack of central command, Bani said without elaboration that "each brigade's circumstances are different."
A panel of southern representatives to the National Transitional Council, Libya's top revolutionary body, said in Benghazi that revolutionaries had captured several high-value figures from the former regime, including Gadhafi's southern intelligence chief. They said the prisoners were undergoing "preliminary questioning" and were being treated well.
The focus now, the delegates said, was on a worsening humanitarian crisis for towns that had sealed themselves off months ago in order to prevent Gadhafi forces from entering.
A cluster of southern towns have had no power or potable water for more than two months, said Ali Kulama Mohamed, the transitional council representative for the town of Murzuk.
"There's a very, very terrible humanitarian situation with regards to aid and food provisions, especially for children," Mohamed said. "We request urgent assistance from the executive committee and from international humanitarian groups."
Libyans in the south are worried that after decades of neglect by Gadhafi's regime, they're now in danger of being excluded from politics and development in the post-Gadhafi era.
The representatives complained that they still must drive their sick and wounded on a grueling two-day journey through the desert to Benghazi for treatment, even though they've secured landing strips for medical evacuation helicopters.
"For months, we've had no electricity and no communications, and nobody cares," said Mohamed Saleh, a petroleum engineer from the southern town of Gatran. "We've had diabetic people die because they couldn't get treatment in time. We can receive planes now, but none have come."
"And in this new government they're talking about now," Saleh added, "we're still not hearing about representation for the south."
Also on Thursday, the Tunisian government announced the overnight arrest of Gadhafi's former prime minister, Al Baghdad al Mahmoudi, on charges of illegally entering the country. He and two other Libyans were found without visas near Tunisia's border with Algeria, according to news reports. The three were to appear before a Tunisian judge.
(Mark Seibel in Washington and McClatchy special correspondent Mohannad Sabry in Cairo contributed to this article.)
MORE FROM MCCLATCHY
Follow Hannah Allam's reports from the Middle East on Twitter.