Libyan strongman Moammar Gaddafi's forces had taken control of the oil city of Ras Lanuf on Friday aside from out-gunned pockets of resistance, medics in contact with rebel fighters said.
"At the moment it's 10 dead and dozens injured from Thursday's fighting, and that's likely to rise significantly. We believe there are many more bodies in the area," Doctor Salem Langhi said from the frontline town of Brega.
"Ambulances have not been allowed to go there to Ras Lanuf, the army is blocking the road," he said, referring to Gaddafi's loyalist force, which shelled the town on Thursday and drove off anti-regime rebels.
"We have been told by the rebel fighters that there are still pockets of resistance in Ras Lanuf, and there is still some fighting, but as of now the army is in control of the area," Langhi said.
"They have total supremacy. They have been firing with ships and they have control of the air," he said, confirming reports from rebel commanders in Benghazi of a major offensive from the Tripoli regime.
State television said on Thursday that loyalist forces had "cleansed" Ras Lanuf, and AFP journalists in the town saw rebel forces in full retreat and army tanks advancing five kilometres (three miles) east of the city.