Clashes between cattle raiders killed 24 people in Sudan's south, the army said today, in a region where authorities have yet to disarm the population fully before an independence referendum next year.
Separately, an international think-tank warned that the African Union must be better prepared for the south's possible secession in eight months, or the chance that Khartoum's Islamist government might try to derail the vote.
South Sudan won autonomy from the north of Africa's largest country in a 2005 peace deal ending 22 years of civil war, and will vote in the referendum due in January 2011 on whether to become a fully independent nation.
In the latest tribal clashes, which killed an estimated 2,500 people in 2009 alone, south Sudan's separate army said cattle raiders from the oil-producing Unity state attacked herders in neighbouring Warrap state.
"Some 15 people were killed from Warrap state and nine from Unity," said south Sudan army spokesman Malaak Ayuen Ajok. The clashes began on Wednesday morning and were continuing, he added.
After decades of civil war and no stable government, southern Sudan's mostly agricultural and cattle herding people armed themselves to defend their livelihoods.
Many analysts say that disarming them is vital for the region's stability before the referendum.
"Most of Warrap state has been disarmed although there are still some civilians with weapons. Meanwhile in Unity we have not started yet," Mr Ajok said, adding that the army was moving to begin disarmament there too.
The International Crisis Group think-tank warned the African Union and Sudan's nine neighbouring nations that they must prepare for a vote for secession, but also the possibility that Khartoum may disrupt the referendum, prompting a unilateral declaration of independence by the south.
"Attempts to delay or derail the exercise are not out of the question," the ICG said in a report published on Thursday. "If pushed into a corner the possibility of (a) unilateral declaration of independence is very real," it added.
The ICG said regional players did not have a coordinated policy on such an outcome, which could reignite Sudan's north-south conflict if it were not handled well.
"If either side abrogates the (north-south deal) a return to conflict is likely and would undoubtedly affect the region and draw in some of its militaries," the ICG said.
"(Their) preparations should include clear modalities for extending official recognition to the south if it votes for independence and developing policy responses to alternative scenarios including unilateral declaration of independence," it added.
Africa's longest running civil war has raged on and off since 1955 and engulfed the entire region in proxy wars and conflict, claiming an estimated 2 million lives and driving 4 million people from their homes.
Differences over ethnicity, ideology, religion and oil fuelled the conflict which ended in 2005 with a shaky north-south national coalition government and an autonomous authority in the south.
Reuters