Libya is bracing for another day of mass protests against the rule of Muammar Gaddafi, raising fears of fresh conflict between anti-government protesters and loyalist forces.
Government forces have set up checkpoints in Tripoli, the capital, ahead of a call by opposition groups to hold rallies after noon prayers on Friday.
Some news agencies have also reported a crackdown on foreign journalists, saying security guards have attempted to block their movements. Internet services have also reportedly been disrupted in Tripoli and the eastern city of Benghazi.
Residents in the capital have said they are preparing for a violent crackdown by pro-Gaddafi soldiers, who they say have been roaming the city in civilian cars.
Air strikes
Friday's action comes amid more reports of battles between loyalist forces and anti-Gaddafi fighters in strategic cities.
Opposition fighters said Libyan forces carried out an air strike near a military base on the western outskirts of Ajdabiya, a town captured by the opposition, but said there was no casualties or damage.
Witnesses said a bomb was dropped on Friday and other fighters say two rockets were fired at the base near the eastern town, but also missed.
Al Jazeera reporters near the town say sandstorms have hit the region, making further strikes unlikely.
But Hoda Abdel-Hamid, Al Jazeera's correspondent in the eastern city of Benghazi, said she had heard reports that volunteers going to the front line of fighting were feeling "very vulnerable from the air".
Other clashes between Gaddafi loyalists and opposition have been reported in Ras Lanuf, the eastern oil port 660km from Tripoli, and in Az-Zawiyah, 50km west of Tripoli.
Government forces are said to be battling to regain control of opposition-held towns close to Tripoli, trying to create a buffer zone around what is still Gaddafi's seat of power.
Opposition protesters in the country's east have set up advanced positions 50km west of Brega, which lies in between Gaddafi's hometown of Sirte and the opposition-held port of Benghazi, and sits near ethnic fault lines between tribes loyal to the leader.
Fighters, who are poorly equipped and not well trained, are also said to have pushed further west on Friday, heading along the main coastal road out of Uqayla, a village 280km from Benghazi.
The AFP news agency said six pick-up trucks were spotted five miles out of the village, mounted with heavy machine guns.
Funerals held
Meanwhile, hundreds of mourners have buried victims of clashes between pro- and anti-government forces in the country's east, where the opposition beat back an offensive by forces loyal to Gaddafi.
Human Rights Watch confirmed at least 14 deaths from the fighting in Brega as of Thursday morning, including a 13-year-old shepherd named Hassan Umran.
Saif Gaddafi, a son of the Libyan leader, told a British broadcaster that Thursday's air strikes were meant to scare opposition protesters away, not kill them.
However, the air strikes failed to dislodge opposition fighters from the oil-rich area.
Dozens of people marched in a funeral procession in Ajdabiya on Thursday, with five coffins held aloft en route to the cemetery there.
"For the people of Ajdabiya, these men are martyrs to their revolution. And the more of their comrades who are killed, the more they are determined to defeat Muammar Gaddafi," reported Jacky Rowland, Al Jazeera's correspondent in the city.
Mourners shouted slogans against Gaddafi, including: "The blood of martyrs will not be spilled in vain"; "Gaddafi get out, Libyans don't want you!"; and "Gaddafi you're crazy!".
A crowd of anti-government activists packed into vehicles and drove to the cemetery, where they fired into the air and said prayers honoring those who had been killed.
PHOTO CAPTION
A pro-revolution soldier holds a rifle on a checkpoint in Brega March 4, 2011
Al-Jazeera