Forces loyal to Libyan leader Moammar Gadhafi have hammered rebels in the west with heavy weapons, as separate fighting creeps toward the capital, Tripoli.
Reporters at the frontline near the rebel-held western town of Zintan say government forces launched rockets during intense fighting Sunday. Elsewhere, rebels say clashes killed at least six at Dafniya, just west of rebel-held Misrata.
In Zawiyah, 50 kilometers west of Tripoli, Libyan rebels regrouped and clashed with pro-Gadhafi forces weeks after troops had forced the rebels' retreat. A highway that serves as a major supply route between Tripoli and Tunisia was closed as a result of the fighting. A rebel fighter said troops have killed several of his comrades since fighting began Saturday, with government forces getting reinforcements.
Rebels briefly took control of Zawiyah in March but were beaten back by pro-Gadhafi forces.
If the rebels are able to take control of Zawiyah and other towns nearby, they could cut off Tripoli's already-meager supply line. A naval blockade and NATO airstrikes have left the capital largely isolated.
Late Saturday, western news reports said loud blasts from apparent NATO airstrikes rocked the Libyan capital.
Pro-government forces also have shelled the western town of Zlitan as well as the rebel-held city of Misrata, where medical officials say at least 30 people were killed on Friday.
U.S. officials traveling with Secretary of State Hillary Clinton in Africa say Libya's situation will feature prominently in her remarks Tuesday at an African Union meeting in Ethiopia.