TRIPOLI: A high-ranking African Union delegation was on its way to Libya on Sunday to present a blueprint for a ceasefire.
On the ground, NATO destroyed key ammunition stockpiles and armored vehicles in air strikes across the country, while heavy fighting continued around the key crossroads town of Ajdabiya.
African Union mediators left Mauritania for Libya, where they were to attempt to negotiate a ceasefire.
Presidents Mohamed Ould Abdel Aziz of Mauritania, Amadou Toumani Toure of Mali, Denis Sassou Nguesso of Congo and Jacob Zuma of South Africa, left mid-morning and were traveling separately to Tripoli, and then on to the opposition stronghold of Benghazi.
"They have just left, each in his own plane," an official Mauritanian source told AFP.
The delegation also includes Ugandan Foreign Minister Henry Oryem Okello, representing Yoweri Museveni, the fifth head of state making up the AU panel.
Earlier on Sunday, the mediators reiterated their appeal for "an immediate end to all hostilities" and proposed a transition period to adopt reforms in the insurrection-hit country.
They were due to meet Libyan leader Moamer Qaddafi in Tripoli and leaders of the rebellion in Benghazi.
Loud explosions rocked the battleground town of Ajdabiya for a second day Sunday, as rebel fighters advanced cautiously after suffering a major reverse at the hands of loyalists.
An AFP correspondent in rebel-held territory east of the town heard some 10 massive blasts in the space of minutes as the two sides disputed the strategic road junction on the east’s coastal and desert highways.
"There is intense shelling of the town from the west," resident Hafeth Zwai told AFP by telephone.
He said he had no idea what casualties or damage the artillery bombardment by forces loyal to Qaddafi was causing as he was afraid to leave his home.
On Saturday, after advancing towards the oil refinery town of Brega, some 80 kilometres (50 miles) further west on the central coast, rebel forces ran into a loyalist counter-offensive that saw them pushed all the back to the eastern edge of Ajdabiya.
The town itself was turned into a battlefield between the rival fighters.
NATO aircraft struck ammunition stockpiles east of Tripoli that were being used to resupply Qaddafi’s forces which the alliance said had been involved in shelling innocent civilians in the besieged third city of Misrata, the rebels’ last major bastion in the west.
NATO said it continued to target forces who fired on civilians despite the loyalists’ tactic of shielding themselves or their weapons behind bystanders.
"In addition to hitting their supplies, our aircraft successfully destroyed a significant percentage of the Libyan government’s armored forces," General Charles Bouchard said in the statement.
"Some of these armored forces also were involved in the indiscriminate shelling of Misrata," he added.
The mission to protect civilians was being made difficult by the use of women and children as human shields by government troops striking at rebel fighters in the heart of communities, NATO said.
"We have observed horrific examples of regime forces deliberately placing their weapons systems close to civilians, their homes and even their places of worship," said Bouchard.
"Troops have also been observed hiding behind women and children. This type of behavior violates the principles of international law and will not be tolerated," he added.
Qaddafi’s deputy foreign minister, Khaled Kaaim, said late Saturday in Tripoli that two rebel helicopters violating the no-fly zone were shot down in the Brega region.
Kaaim hit out at the NATO forces in charge of applying Security Council Resolution 1973 imposing the air exclusion zone over Libya, saying: "NATO on Saturday permitted the rebels to violate this resolution and use combat helicopters."
NATO said its warplanes intercepted a MiG-23 fighter jet flown near Benghazi by a rebel pilot earlier Saturday and forced him to land after he violated the no-fly zone.
North Korea has ordered its citizens in Libya not to return home in an apparent bid to block news of civil uprisings in the Arab world from reaching the isolated communist state.
Pyongyang, in a message sent to its embassy in Tripoli, told some 200 North Korean workers not to return and to follow local authorities’ advice, South Korea’s Yonhap news agency said, citing a source familiar with North Korean affairs.