Forces loyal to Muammar Gaddafi, the Libyan leader, have continued a large-scale military offensive against rebels in the country's east, launching air strikes at the oil-producing towns of Ras Lanuf and Brega.
Some of the fiercest fighting on Friday was reported from Ras Lanuf, where rebels launched a counter-attack to stem the advance of pro-Gaddafi forces. The rebels had earlier lost control of pockets of residential areas, and were clinging on to other parts of the town, sources told Al Jazeera.
Plumes of smoke were seen billowing from an oil installation in the city, reportedly the result of military air strikes.
Ibrahim al-Alwani, a rebel fighter, said he and comrades still in Ras Lanuf had seen government troops in the town centre.
"I saw maybe 150 men and three tanks," he told Reuters on Friday morning. "I can hear clashes."
The government troops had landed by boat near the Fadeel hotel in Ras Lanuf on Friday, Mohammed al-Mughrabi, a spokesperson, told Reuters.
Rebels appeared to have withdrawn on Friday to their last main checkpoint, about 15km to the east of the town's centre.
"They came from the air, they came from the sea, and there were rockets everywhere. It was a big surprise for us,'' one rebel fighter, Mustafa Mehrik, a 39-year-old coffeeshop owner, said in Brega, a rebel-held town to the west where many of the casualties from the attack were taken.
"Everyone is worried. Today they say there will bring heavy weapons from Benghazi.''
Foreign journalists faced significant hurdles getting information out of Ras Lanuf, but Libyan state television on Friday aired footage of people fleeing the city and of pro-Gaddafi forces searching houses for weapons.
Pro- and anti-government forces are locked in intense fighting for control of several other cities and towns along the coastline to the east of Tripoli, including Bin Jawad.
|Pro-Gaddafi forces appeared to be in control of the centre of Az Zawiyah on Friday evening [AFP]
In Az Zawiyah, to the west of Tripoli, the revolt appeared all but crushed, witnesses said. The government took foreign journalists on a tour of the city on Friday evening.
The journalists said the main square of the city appeared to be firmly under government control.
An oil refinery there has also resumed operations, according to an official.
It appears that with fresh clashes reported in Misurata, Ras Lanuf and Brega, the frontline is now advancing eastwards, towards Benghazi, a rebel stronghold.
Benghazi was the place where the protests against Gaddafi first began last month, quickly escalating into a a mass uprising against his more than 41-year-old rule.
Hoda Abdel-Hamid, Al Jazeera's correspondent in Benghazi, said that thousands of people had gathered there on Friday in support of the rebel forces, expressing optimism that they could hold on to the city if attacked by Gaddafi's military.
"Many people have died in our struggle in Ras Lanuf and in Benghazi, but the youth has chosen to fight on rather than see this rule continue, and they will fight for the sake of God," a blind imam proclaimed ahead of Friday prayers.
"But if you look at the country and what's happening ... the Gaddafi forces are certainly trying to keep or to regain control of all the oil facilities around the country," Abdel-Hamid reported.
For Gaddafi's forces to retake Tobruk, Libya's eastern-most oil port, they would have to pass through Benghazi, she said.
|Flashpoint cities in Libya
Benghazi has been serving as a rear support base for many rebels travelling to and from the front lines.
Abdel-Hamid reported that if Ras Lanuf was lost entirely, it would likely strike a strong blow to the rebels' morale. The rebels readily admit that they do not have the firepower to counter the pro-Gaddafi forces, she added.
She reported that a significant number of rebels had retreated from the fighting in Ras Lanuf, and that the mood in Benghazi was "one of apprehension and tension" of what is going to happen in the next few days".
The Military Supreme Council, a leadership body of the military commanders who are with the rebels, is currently attempting to structure the rebels' response and to ensure that they are deployed tactically, Abdel-Hamid reported.
Railing against rebels
Buoyed by the successes on the frontline, a confident-looking Saif al-Islam Gaddafi, the son of Muammar Gaddafi, levelled fresh charges against the rebels on Friday.
|Thousands of anti-Gaddafi protesters attended Friday prayers in Benghazi, expressing their defiance
Addressing journalists at a press conference, he alleged that anti-government militias had been mutilating the bodies of opponents.
He also said the actions of the rebels to seize military ammunition depots and bases were not the actions of "advocates of democracy" or "reformists".
He said that thousands of people were being held "hostage" by the rebels.
In an earlier interview with Reuters on Thursday, Saif al-Islam declared that the time had come for full-scale military action against the rebels.
Late on Friday, Libyan state television reported that the government was prepared to offer amnesty to any rebels who chose to lay down their weapons.
"Whoever lays down weapons shall not be punished, and may God forgive them for their previous acts..." a news ticker on the state-run Al Shababiya television station read.