Six days of tribal clashes in a remote desert town in southern Libya have killed 147 people, the country's health minister has said.

Fatima al-Hamroush said in Tripoli on Saturday that the fighting in Sabha has also left 395 wounded and 180 people have been transported to the capital Tripoli for emergency treatment.

The clashes in the oasis region some 400 miles south of Tripoli highlight the fragile authority of the Libyan government, particularly in the isolated settlements that dot the southern desert.

With only a nascent national army and police force, Libya's ruling National Transitional Council relies on militias composed of former rebels to keep the peace, and the country's vast distances make it difficult to deploy them to trouble spots.

Muammar Gaddafi's 40 years in power have left behind a patchwork of local rivalries. The Sabha fighting pits southern Libyan Arab tribes that reportedly had close connections to Gaddafi against the African Tabu tribe, which fought against him.

Sabha residents said that the rivalry burst into open conflict on Monday after a Tabu shot a member of the Arab Abu Seif tribe, and then a delegation of Tabu elders and armed men was ambushed on its way to peace talks.

The Tabu and Arab tribes fought in another oasis region, Kufra, in February, and Sabha residents said the two groups exchanged fire using automatic rifles, mortars and rockets. A spokesman for the Tabu, Mohammed Lino, said that about 70 Tabu homes were burnt and 100 families had been forced to flee the city during the past week of violence.

A video posted on YouTube on Thursday, purportedly from Sabha, showed men in civilian clothes and the occasional camouflage jacket armed with assault rifles moving through a maze of alleys, as flames rose from burning cars parked nearby. The authenticity of the video could not be verified.

Libya's Tabu have kinsmen living across the border in Chad, and the defence ministry said on Saturday that it sent a number of militia and national army soldiers to the country's southern border in case other African tribes try to join the fight. It also dispatched airplanes to survey the area.

Other militia as well as tribal chiefs from around Libya have been dispatched to Sabha over the past few days. On Thursday they said they brokered a ceasefire that residents said has held in the city, but not outside.

Lino said that fighting continues just south of Sabha. He said he travelled to Tripoli on Saturday to meet with a number of cabinet ministers to try and resolve the crisis.

Other Tabu leaders, frustrated with the slow pace of government action, say that Tripoli's leaders have not protected them against attacks from Arab tribes in Sabha.

The government said it is trying to move relief supplies to the area. Hamroush said that Tripoli has sent large amounts of emergency aid to the city, but that there is still an urgent need for medical supplies.

A UN team in Libya said that they have also assisted with aid, and supplied additional medical kits.