Several hundred tribal elders gathered Thursday in the Libyan capital in what a government official said was a show of widespread support for Muammar al-Qaddafi. Rebels dismissed the claim as bogus.

In Rome, U.S. Secretary of State Hillary Rodham Clinton said the best way to protect Libya's people is to get Qaddafi to leave power. "This is the outcome we are seeking," she told representatives from 22 nations and organizations.

Qaddafi has tried to crush an 11-week-old armed rebellion against his rule, including by shelling rebel positions, particularly in the western part of the country that largely remains under his control. Rebels hold most of eastern Libya.

On Thursday, Libyan troops fired Grad rockets toward the outskirts of the rebel-held town of Nalut in a remote western mountain area. A day earlier, Qaddafi loyalists shelled the port area of the city of Misrata, the biggest rebel stronghold in the west, killing four people, including two children, from a migrant workers' camp as an aid ship was docked there.

Asked about Wednesday's shelling, Libyan government spokesman Moussa Ibrahim said the port area is within the range of fire of the Libyan forces and that "we won't allow any ship of any kind to come in unless it has our permission."

Last week, Libyan forces were caught by NATO laying anti-shipping mines off Misrata. NATO vessels have been searching for mines since then. Two were detonated shortly after the mine-laying was detected.

Britain's military said Thursday that its naval forces knocked out a mine left about a mile from Misrata's harbor. A Royal Navy vessel destroyed the 220 pound floating bomb Wednesday, the British military said.

The port is the only lifeline for Misrata, a city of 300,000 that has been besieged by Qaddafi's forces for more than two months.

Ibrahim said the Libyan army is trying to block sea access to prevent weapons from reaching the rebels. The regime's failure to capture Misrata, a rebel stronghold, would make it difficult to partition Libya, perhaps the only scenario in which Qaddafi could hope to cling to power in the western part of the country.

In Tripoli, meanwhile, foreign reporters were taken by government minders to a large tent where hundreds of tribal elders had gathered. Reporters were told that about 2,000 chiefs were present, that they represent 850 Libyan tribes and that the gathering was organized by the tribes, not the regime. The government also released a list of what it said were the names of the tribes.

"It's another proof that the Libyan people are rallying behind the leadership," Ibrahim said of the gathering. Several speakers at the conference called for national unity, urged rebels to disarm and demanded that the international community halt its bombing campaign, which began in mid-March with the aim of protecting Libyan civilians against Qaddafi's troops.

Ibrahim said the tribal gathering was a counterpoint to Clinton's call for Qaddafi's ouster. "What voice is more important, Hillary Clinton's voice or the voice of 2,000 tribal leaders of Libya?" he said.

A rebel spokesman dismissed claims that those attending the Tripoli conference represented all Libyan tribes.

"Libya doesn't have 850 tribes," said the head of the political committee of the rebel's Transitional National Council, Fathi Baja, in the eastern city of Benghazi. "Qaddafi is just a big liar. ... He never had any legitimacy. The Libyan people did not choose him."

Na'eem Jeenah, director of the Afro-Middle East Center in Johannesburg, South Africa, has said Libya has about 140 tribes and clans. He has said Qaddafi has manipulated tribal rivalries and made regular payouts to tribal leaders to juggle his long tenure in power.