BENGHAZI: Tribal fighters opposed to Moamer Qadhafi have clashed with the strongman’s forces in the oasis city of Sabha, rebels said, as regime troops went on the offensive at key Libyan flashpoints.

The fresh wave of fighting comes as Turkey said it has offered Qadhafi guarantees to leave Libya and Russian envoy Mikhail Margelov said he would soon visit Tripoli to try to find a solution to the conflict.

Fighters of the Awlad Suleiman tribe, a rival to the Qadhafis, “liberated several streets” in Sabha, 800 kilometres south of Tripoli and a bastion of support for Qadhafi, the rebel National Transitional Council said on Saturday.

Qadhafi’s forces opened fire, killing one man, the NTC said in a statement.

Sabha, with a population of some 100,000 people and home to an important military base, had until now been untouched by the unrest which has swept much of the north African oil-rich nation since a popular uprising against Qadhafi’s four-decade authoritarian rule erupted mid-February.

Fighting in the important agricultural city famed for its Fort Elena castle followed two days of anti-Qadhafi protests there, the statement said, issued in the rebels’ eastern capital Benghazi.

“Major protests began on Friday in the Mansheya district (of Sabha) ... with young people acclaiming the revolution of February 17, raising the flag of independence and demanding Qadhafi’s departure,” the statement said.

“Qadhafi loyalists, some in plain clothes, opened fire with live ammunition and two protesters were hit. They were taken to hospital where they were detained by Qadhafi’s men,” it added.

The rebels said pro-Qadhafi forces were on Saturday shelling the western city of Ghadames some 600 kilometres southwest of Tripoli, close to the borders with Tunisia and Algeria.

Known as the “pearl of the desert,” the oasis boasts a UNESCO World Heritage site and is famous for its Roman-era ruins.

“The people of Ghadames appeal to UNESCO and international organisations to protect the ancient city,” the rebels said in statement.

They also reported clashes on Friday and Saturday at Kekla and Bir al-Ghanem in the mountainous Jebel Nafussa region west of Tripoli where there has been weeks of fighting.

Pro-Qadhafi forces had tried to enter the town of Yafran in the same area, and that there had been “fierce clashes.” The rebels, who control vast swaths of eastern Libya as well as the city of Misrata and a sprinkling of towns in the west, also reported fighting at Dafnia near Misrata on Saturday.

A rebel said that on Friday, 20 people were killed as Qadhafi’s forces had bombarded the Dafnia area with Grad rockets, heavy artillery and tank shells.

Turkish Prime Minister Recep Tayyip Erdogan said his government had offered exit “guarantees” to the embattled Libyan leader, whom rebels have been trying to oust since February following a bloody crackdown on pro-reform protests.

Qadhafi “has no other option than to leave Libya - with a guarantee to be given to him,” Erdogan said on NTV television.

“We have given him this guarantee. We have told him we will help him to be sent wherever he wants to go,” he added, without elaborating. “We have received no reply so far.” Tripoli has this week seen the most intense Nato air raids since the international military campaign began on March 19 under a UN mandate to protect Libyan civilians.

US Defence Secretary Robert Gates warned however that the air war on the strongman’s forces could be in peril because of military shortcomings.

Gates, the Pentagon chief, expressed concern on Friday with half of the countries in the 28-member Nato alliance not participating in the campaign, saying many simply did not have the wherewithal.

On Saturday, two blasts shook Tripoli in the afternoon, witnesses said, in apparent air strikes targeting the Salaheddin and Ain Zara districts. Residents said several waves of blasts also rocked the city on Friday.

In a military update on Friday’s strikes, the British defence ministry said its fighters had destroyed four tanks “hidden in an orchard” near the town of Al-Aziziyah, southwest of Tripoli.

Tornado and Typhoon jets also bombed a military base at Al-Mayah on the western outskirts of the capital, it said.

Nato said a tank and a rocket launcher were also targeted on Friday near Misrata.

In Moscow, Russian President Dmitry Medvedev’s special envoy Mikhail Margelov said he would visit Tripoli to try to find a solution to the conflict, having met the opposition in their Benghazi stronghold.

Almost 900,000 people have fled Libya since the outbreak of the conflict, which has cost thousands of lives, according to UN agencies.