An armed convoy of dozens of vehicles, believed to be carrying hard-core loyalists of Moammar Gaddafi, including his security chief, crossed the southern border into Niger on Tuesday, raising questions about the fugitive leader’s whereabouts and whether he was preparing to flee.

Rebel leaders said Gaddafi was not in the convoy, but they were unsure exactly who was in the vehicles. Fighters opposing Gaddafi have no access to the desert south of Sabha, which lies on the edge of the Sahara and about 300 miles from Libya’s southwestern border with Niger. The border is not secured, leaving the rebels dependent on their neighbors to stop nefarious activity.

“Our military said there was a convoy that crossed into Niger,” said Jalal el-Gallal, a spokesman in Tripoli for the rebels’ governing Transitional National Council. “As to the content, I don't think anyone has any idea what was inside.”

The head of the council, Mustafa Abdel Jalil, has asked Niger to lock down its border with Libya. But according to council members, the loyalist convoy was welcomed into the country. Officials in Niger confirmed that the convoy entered but said Gaddafi was not inside, Niger’s foreign minister, Bazoum Mohamed, told al-Arabiya television.

On Wednesday, the spokesman for Tripoli’s new military council said Gaddafi was still in Libya, trapped within a 40-mile radius and surrounded by rebel forces, the Associated Press reported.

The spokesman, Anis Sharif, would not identify the 40-mile area. But he said Gaddafi had been tracked using high technology and human intelligence. Sharif told AP that the former rebels are preparing to either detain Gaddafi or kill him.

The hunt for Gaddafi has been a disorganized and a difficult task that depends on eyewitness accounts throughout the country. Various reports have placed the leader in different locations throughout his tribal heartland, a triangle between his coastal home town of Sirte, the oasis town of Bani Walid to the west and the city of Sabha on the edge of the Sahara in the south. But council members insist that they have a solid idea of where Gaddafi is.

On Tuesday, NATO said it was not its job to search for Gaddafi and could not speak about the reports the alliance receives about movements on the ground.

“To be clear, our mission is to protect the civilian population in Libya, not to track and target thousands of fleeing former regime leaders, mercenaries, military commanders and internally displaced people,” said Col. Roland Lavoie, a NATO spokesman.

The reported convoy border crossing comes as negotiations continued for the surrender of the loyalist town of Bani Walid, about 100 miles southeast of Tripoli. Gaddafi’s son, Saif al-Islam Gaddafi, is believed to be in Bani Walid.

As the hunt for Gaddafi continued, his die-hard supporters remained defiant Tuesday, promising to resurrect his power structure and fight.

“We are fighting and resisting for the sake of Libya and all Arabs,” Moussa Ibrahim, Gaddafi’s spokesman and the public face of his government, told the Syria-based al-Rai television station, a pro-Gaddafi channel. “We are still strong and capable of turning the tables on NATO.”

To counter reports that Gaddafi was planning to flee, Ibrahim told al-Rai that the longtime ruler was in “excellent health, planning and organizing for the defense of Libya.”

After he spoke, a video was posted on rebel Facebook pages of fighters detaining Gaddafi's deputy foreign minister, Khalid Kaim. The video showed Kaim sitting on a bed, being interrogated by rebels who called him a “liar” and a “dog” and accused him of using foreign mercenaries against them.

The arrest was the latest in a series of high-profile detentions of Gaddafi loyalists. Kaim and Ibrahim became the public faces of the Gaddafi government in Tripoli during the uprising that began in February.