Several hundred tribal elders have gathered in the Libyan capital in what a government official said was a show of widespread support for Muammar Gaddafi.
Meanwhile in Rome, US Secretary of State Hillary Clinton said the best way to protect Libya's people was to get Gaddafi to leave power. "This is the outcome we are seeking," she told representatives from 22 nations and organisations.
Gaddafi 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, Gaddafi 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 the shelling, Libyan government spokesman Moussa Ibrahim said the port area was 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".
The port is the only lifeline for Misrata, a city of 300,000 which has been besieged by Gaddafi's forces for more than two months.
In Tripoli, meanwhile, foreign reporters were taken by government minders to a large tent where hundreds of tribal elders had gathered. They were told that about 2,000 chiefs were present, that they represented 850 Libyan tribes and that the gathering was organised by the tribes, not the regime.
"It's another proof that the Libyan people are rallying behind the leadership," Mr Ibrahim said of the gathering.
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. "Gaddafi is just a big liar... He never had any legitimacy. The Libyan people did not choose him."