Libyan rebels pulled back their last main checkpoint in Ras Lanuf on Friday, setting it up 15-20 km (10-13 miles) to the east, and said their forces were continuing to fight troops loyal to Muammar Gadhafi in the eastern oil town.
"This is our last checkpoint, ahead are clashes. The clashes are in the residential area (of Ras Lanuf)," rebel fighter Youssef Mohannad told Reuters at the checkpoint, near an oil refinery. Smoke still poured out of one stack at the refinery, suggesting at least some production was continuing.
Other rebels around him said there had been an air, sea and land attack on Ras Lanuf, one of the main oil terminals in the area.
After thuds and booms were heard overnight in the town of Brega, further east of Ras Lanuf, there was no sound of heavy weaponry being fired on Friday morning, a Reuters correspondent reported.
He said rebel forces had moved at least two tanks and three armored personnel carriers forward towards their frontline.
Ibrahim al-Alwani, a rebel fighter in Brega, an east Libyan town, told Reuters that he and comrades still in Ras Lanuf had seen government troops in the town center.
On Thursday, government warplanes and gunboats bombarded rebel positions in Ras Lanuf, and bombs or missiles landed a few (miles) from a Ras Lanuf oil refinery and close to a building of the Libyan Emirates Oil Refinery Company building, a Reuters witness said.
"One bomb landed on a civilian house in Ras Lanuf," rebel fighter Izeddine Sheikhy told Reuters.
The bodies of four rebels killed in the fighting were brought to a hospital in Ajdabiyah, further east, along with 36 wounded, said Ibrahim Saeed, a doctor at the hospital.
Rebels also reported an air strike on Brega, another oil port 90 km (50 miles) to the east, on Thursday.
West of Tripoli, the revolt in Zawiyah appeared all but crushed, with insurgents clinging to only parts of the shattered city. Residents described scenes of carnage, with women and children among the dead.
One fighter said rebels had retaken the heart of Zawiyah from the army overnight Thursday, but authorities have kept journalists away from the town, about 50 km (30 miles) west of Tripoli.
"The really concerning thing is the reports we keep hearing of hospitals being targeted, of ambulances being used to transport troops and of medical supplies running out," said Baroness Amos, U.N. Under Secretary-General for humanitarian affairs.