Libya's interim government has sent envoys to neighboring Niger in an effort to prevent ousted leader Moammar Gadhafi and his entourage from escaping justice by fleeing across the border as the hunt for the fugitive strongman intensified.

A senior Libyan official said Wednesday the delegation will discuss efforts to secure the two countries' long, desert frontier. He said the National Transitional Council has asked that no nation accept Mr. Gadhafi.

Niger's government confirmed the former strongman is not in the country. It said Niger officials are acting in consultation with the NTC and that recent movements of Libyan convoys across the border have been much smaller than reported.

Justice Minister Marou Amadou said Wednesday a total of 18 people – including five Niger citizens – in four vehicles had entered the country from Libya in recent days. He said there was no convoy of 200 vehicles, as had been reported by some media.

Other Niger officials confirmed that senior members of Mr. Gadhafi's government – led by his own security chief, Mansour Dhao – had crossed the border together with Tuareg fighters from Niger who had joined the former leader's forces.

In Washington, the State Department said U.S. officials have urged North African countries to tighten border controls, arrest fleeing Gadhafi government officials and impound funds or other wealth they may be carrying. Spokeswoman Victoria Nuland acknowledged that news reports about large convoys crossing Libya's southwest frontier were “overblown.”

Meanwhile, conflicting reports emerged about whether NTC forces have cornered Mr. Gadhafi in Libya's southern Sahara desert.

The spokesman for Tripoli's military commander said Wednesday provisional authority forces have advanced to within 65 kilometers of his location and surrounded the area. He said Mr. Gadhafi “cannot escape,” adding that former rebel fighters are expected to move in soon.

But senior Libyan defense officials dismissed the claim, saying Libya's new rulers have no idea where the fugitive former leader is. The New York Times quotes the NTC's military press liaison as citing unconfirmed reports that Mr. Gadhafi may be in yet another convoy moving toward the remote Niger frontier.

Niger borders Burkina Faso, which had previously announced it would grant asylum to Mr. Gadhafi. On Tuesday, however, Burkina Faso officials said the former strongman would be arrested if he arrived there.

Also Wednesday, NATO said its warplanes bombed several tanks and other armored vehicles around Mr. Gadhafi's hometown, Sirte. The first fighting in days was reported near Sirte on Tuesday, but NTC commanders said the clashes did not mark the launch of an all-out bid to capture the city.

In the desert outpost of Bani Walid, negotiators from Libya's National Transitional Council say they are committed to avoiding bloodshed where they are pressing tribal elders tied to Mr. Gadhafi's former rule to surrender.

Town elders and NTC representatives met Tuesday for talks at a mosque on the town's outskirts, but the elders were later confronted by angry citizens, including Gadhafi supporters, who fired into the air and sent them fleeing.