As the first group of a dozen vehicles pulled into Niger's capital, Niamey, a customs official said it included Mansour Dao, Gaddafi's security chief and a key member of his inner circle, as well as around 12 other Gaddafi regime officials.

Still, efforts to negotiate the peaceful handover of one of the most crucial of those bastions, the city of Bani Walid, proved difficult.

Tribal elders from Bani Walid who met Tuesday with former rebels were confronted by angry residents of the city, including Gaddafi supporters, who fired in the air and sent them fleeing, mediators said. Many in Bani Walid remain deeply mistrustful of the forces that have seized power in Libya and are reluctant to accept their rule.

Some former rebels depicted the flight to Niger as a major exodus of Gaddafi's most hardcore backers. But confirmed information on the number and identity of those leaving was scarce as the convoy made its way across the vast swath of desert - over 1,000 miles - between populated areas on the two sides of the border.

Gaddafi himself is not in the convoys, the US State Department said.

AP