Libyan rebels made a renewed effort to push toward the oil port of Brega on Saturday while Muammar Gaddafis forces pounded besieged Misrata to the west with rockets and mortars,insurgents said. Underlining the difficulties faced by the rebels,six were killed and 16 wounded when Gaddafi loyalists fired rockets at a group of insurgents driving along the exposed coastal highway from Ajdabiyah west toward Brega. The rebels attempt to fight their way into western Libya which would eventually allow them to link up with comrades in Misrata has ground to a halt along the eastern coastal stretch from Ajdabiyah to Brega,despite NATO airstrikes. Rebels said some fighters had set up positions on the outskirts of Brega,but with their forces exposed to attacks on the highway and often fleeing back in response they were unable to send more men forward to dislodge Gaddafi loyalists in the town centre. In Misrata,besieged for seven weeks,rebel spokesman Gemal Salem said Gaddafis forces pounded the town with rockets and mortars on Saturday,targeting a diary factory and one that makes cooking oil. He said three people were killed and more than 20 wounded. The US-based Human Rights Watch has accused Gaddafis forces of using cluster bombs which scatter bomblets over a wide area in Misrata. The Libyan government has rejected the allegations. In Ajdabiyah,rebels said Gaddafis forces were ensconced in the centre of Brega,often inside houses while insurgent fighters were themselves more exposed. We have people on the edge of Brega,we control that area only. Nothing has changed inside Brega, said Mohammed el-Misrati,20,after returning to Ajdabiyah to the east.