Libya's new interim leader met the most senior U.S. official to visit Tripoli since the fall of Muammar Gaddafi, though details of Wednesday's talks were not immediately available.
Reuters journalists saw Jeffrey Feltman, a key figure in U.S. Middle East policy, meet Mustafa Abdel Jalil at a public building in the capital. It was not clear when Feltman, who is Assistant Secretary of State for Near Eastern Affairs at the State Department, had arrived in Libya.
Compared to other parts of the country, Tripoli has been relatively stable since forces of the new ruling National Transitional Council (NTC) overran it three weeks ago. NTC fighters backed by NATO are trying to capture at least three towns still held by Gaddafi loyalists.
Gaddafi himself has not been seen in public since June. His fugitive spokesman, Moussa Ibrahim, speaking on a satellite phone, told Reuters the 69-year-old leader was still in Libya, in good spirits and gathering his forces for a fightback.
"The leader is in good health, in high morale ... of course he is in Libya," said Ibrahim, who declined to give his own location. "The fight is as far away from the end as the world can imagine. We are still very powerful, our army is still powerful, we have thousands upon thousands of volunteers."
While his opponents would scoff at the idea of a successful Gaddafi comeback, they have been concerned at the difficulties they have had in taking the final bastions of his support.
Interim government forces are besieging one of those last bastions, Bani Walid, 180 km (110 miles) south of Tripoli, along with Gaddafi's hometown of Sirte on the Mediterranean coast and Sabha, deep in the southern desert.
After a week of fighting NTC forces at Bani Walid have been urging people to leave before they try to storm the town. Scores of cars packed with families left Bani Walid on Wednesday as NTC forces broadcast messages telling them to go and handed out free petrol to help them evacuate.
"There is a lot of random shooting. It is much safer for my children to leave. Gaddafi militia men do not want to negotiate," Fathalla al-Hammali, 42, said, driving away from the town with his three young children.
Loyalist resistance has complicated NTC efforts to normalize life in the oil-rich North African state and the United Nations has voiced fears about the plight of civilians marooned inside besieged pro-Gaddafi towns, particularly Sirte.
GADDAFI STILL MISSING
Gaddafi's whereabouts are unknown. NTC officials have said he could be hiding in one of the outposts like Bani Walid, helping to rally a last stand against NATO-backed forces.
Bani Walid resident Isa Amr, 35, said the town was running out of fuel, food and water, making it impossible for his family to stay any longer. "Rebels gave us some petrol, enough to drive to Tripoli. The rebels are really helping us," he said.
NTC field commanders said people in Bani Walid had been told in radio messages they had two days to leave town.
"I think only 10 percent of the people are Gaddafi supporters. They are fanatics. And the rest are waiting to be liberated. We have given them two more days to leave the city," NTC fighter Abumuslim Abdu said.
The country's new rulers have hesitated to employ heavy-handed tactics to seize Bani Walid, which is the traditional home of the Warfalla tribe, Libya's largest.
Libya's interim rulers have said that, along with taking control of pro-Gaddafi enclaves, capturing or killing the fugitive leader is a priority and only then could Libya be declared "liberated."
The U.S. State Department said one of his sons, Saadi Gaddafi, who arrived in neighboring Niger on Sunday on one of four convoys of senior Gaddafi loyalists to have crossed the southern Sahara desert frontier, was being held there, Reuters reported.
"Our understanding is, like the others, he's being detained in a state guest house," State Department spokeswoman Victoria Nuland said in Washington on Tuesday.
"It's essentially a house arrest in this government facility, is our understanding," she said, adding that Niger was working with Libya's interim rulers on the issue.
Niger said on Monday it was keeping Saadi Gaddafi under surveillance but had not detained him. A government source said on Tuesday that he had been transferred from the northern desert town of Agadez to the capital Niamey late on Tuesday.
"He is in a secure place. Like the others he is here on humanitarian grounds. He is not being sought after. He is under surveillance, not imprisoned," the source said, adding that he was not, however, free to move: "You do not have freedom of movement when you are under surveillance."
Gaddafi and his fugitive son Saif al-Islam are wanted by the International Criminal Court (ICC), though NTC officials have said Libyans would like to try them first.