TRIPOLI: Libya's tribal chiefs have urged a general amnesty for all fighters engaged in the oil-rich nation's civil war, as rebels, meanwhile, braced for a new ground assault by Muammar Gaddafi's forces on Misrata, the main bastion of the insurgents in western Libya. The National Conference for Libyan Tribes called in a meeting that ended late Friday for a “general amnesty law which will include all those who were involved in the crisis and took up arms.” That would be “a means of laying the path ahead for a new era of peace and forgiveness,” a statement said, without providing details on the law or a timetable for its passage. But doubts were cast on the proposal, as the statement referred to rebels as “traitors” and pledged not to “abandon” or “forsake” the strongman, whose ouster the insurgents are demanding. The statement also called for marches to “liberate” rebel-held towns. “The conference also calls all Libyan tribes neighboring the towns and cities hijacked by armed groups to move peacefully in popular marches to liberate those hijacked towns, disarming the armed rebels,” it said. In the port city of Misrata, rebels were bracing for a fresh ground assault by Gaddafi forces, Saturday. Suleiman Fortiya, a Misrata representative from the rebels' National Transitional Council, said troops were massing in Zliten, outside the city. “I am sure there will be a lot of fighting on the ground in the future. That is what Misrata is worried about because he (Gaddafi) is preparing to march on Misrata,” Fortiya said. In Tripoli Deputy Foreign Minister Khaled Kaim said that there will be no let-up in the government's attempts to block off the maritime lifeline to Misrata, which he said is allowing “ships to bring arms to the city and then to evacuate some criminals.” Meanwhile artillery rounds fired by forces loyal to Gaddafi fell in Tunisia Saturday as fighting broke out near the border between Libyan soldiers and anti-Gaddafi rebels. Schools were evacuated and residents scurried for safety in the Tunisian frontier town of Dehiba, which has been hit repeatedly by stray shells in recent weeks as the Libyan rivals fight for control of a nearby border crossing. Fighting has intensified in Libya's Western Mountains region as Gaddafi loyalists and rebels, backed by NATO bombing, reach stalemate on other fronts in the war. Billows of dust and rock marked where at least four projectiles struck on the Tunisian side. The battle is for control of the Dehiba-Wazzin border crossing, which gives the rebels a road from the outside world into strongholds in the Western Mountains region where they are fighting to end Gaddafi's rule of more than four decades. The crackle of small arms could be heard from about four km inside Libya, where rebels and loyalists exchanged fire, but the border post remained open - most of the cars carrying refugees fleeing the fighting.