Libyan rebel forces in besieged Misurata on Saturday pushed back the advancing Gaddafi troops amid fierce battle for the control of the key eastern town of Ajdabiya as African Union leaders embarked on a diplomatic mission to end the conflict.
Gaddafi forces pushed ahead to retake the strategic town of Ajdabiya, the gateway to the opposition stronghold of Benghazi, after forcing the rebels to retreat from the oil town of Brega.
Reports from the east said rebel fighters came under heavy artillery fire from the advancing government forces in Ajdabiya, 860 kilometres east of Tripoli.
Libyan rebels claimed to have pushed back an advance by Gaddafi's forces into Misurata, 214 kilometres east of Tripoli where five people killed in the fighting.
Fierce street fighting was witnessed as Gaddafi's forces mounted an assault on the eastern part of Misurata, the lone major rebel stronghold in the west of the country.
Amid warnings that the situation in Libya was reaching a stalemate, the African Union began a key diplomatic mission to end the crisis.
A group of African Union leaders, including South African President Jacob Zuma, will visit Libya and meet Gaddafi in Tripoli and opposition's Interim Transitional National Council in Benghazi tomorrow to seek an immediate end to the conflict.
"Key on the agenda of both meetings will be the immediate implementation of a ceasefire from both sides and the opening of a political dialogue between the two parties," the South African foreign ministry said in Johannesburg.
The last few weeks have seen a military stalemate grow in the east, with both sides advancing and retreating across enemy lines.
Coming under heavy shelling, the rebels had retreated from the outskirts of Brega and were struggling to hold their ground. Misurata has been the centre of a weeks-long siege with the rebels managing to hold out to their major western post in the face of an advancing Libyan military in other parts of the country.
Severe shortages of food, water and medical supplies are being experienced by the people and hospitals are overflowing with patients, Al Jazeera reported.
Terrified people are crammed into the few remaining safe districts -- five families to a house -- to escape incessant mortar and rocket fire.
A resident was quoted as saying that five people were killed and 10 others were wounded in the fighting today. A rebel spokesman said government troops had advanced on the heavily populated Esqeer district in an effort to loosen the rebels' grip on Misurata.
He said the attack had been repelled and the forces pushed back for now. The AU panel, which will visit Tripoli tomorrow, includes leaders of Congo, Mali, Mauritania, South Africa and Uganda.
The panel will demand an immediate ceasefire, the South African foreign ministry said.
There was no let up in the NATO air strikes as weapons depots of pro-Gaddafi forces near the town of Zintan were hit yesterday.
Al Jazeera said rebels on the western frontline of Ajdabiya, still jittery after becoming a target of NATO 'friendly fire' on Thursday, fled from an artillery bombardment though there was no immediate sign of a government advance.
A three-week NATO air strikes have not done much to help the rebel advance as was being hoped earlier and leaders of the western alliance have acknowledged the limits of their air power particularly with Gaddafi's forces tactics of placing their weaponry in the middle of civilian areas.
Earlier this week, a top US commander warned that the conflict appeared to be turning into a "stalemate".
US General Carter Ham, the head of Africa Command, said in Washington DC that it was unlikely the rebel forces could push Gaddafi out themselves.
He told a Senate hearing on Thursday that the chances of the opposition fighting "their way" to replace Gaddafi is "low likelihood."
Meanwhile, NATO chief Anders Fogh Rassmussen expressed regret over the deaths in the rebel camp in 'friendly fire' by the western military alliance, terming the incident as "unfortunate".
"The situation on the ground is very fluid," Rasmussen said. "We have seen in the past that tanks have been used by the Gaddafi regime to attack civilians."
In a related development, the UN has decided to send a three-member commission under a veteran war crimes expert to probe the human rights excesses in Libya in the ongoing civil war with both rebels and government agreeing to give the panel an access.
The commission, which will be chaired by Prof Cherif Bassiouni, will conduct a thorough inquiry into "all human rights violations in an independent and impartial manner," the UN Human Rights Council spokesperson announced.
The three-member Commission is expected to stay in Libya till the end of this month but it has not formally announced its travel schedule.
The US has slapped sanctions against Libyan Prime Minister and four other top officials besides two companies controlled by children of embattled leader Gaddafi.
"We will continue to expose and impose sanctions on senior Libyan government officials who choose to remain at Gaddafi's side," David Cohen, the Acting Under Secretary for Terrorism and Financial Intelligence, said on Friday in Washington.
The sanctioned officials include Ali al-Mahmoudi Al Baghdadi, Libya's Prime Minister; Shukri Ghanem, Oil Minister; Abdulhafid Zlitni, Finance Minister; Tohami Khaled, Director of Internal Security Office and Bashir Saleh, or Chief of Staff to Gaddafi.