While much international attention remains focused on the conflict in Sudan's Darfur region, recent clashes near a disputed territory along the border of northern and southern Sudan have raised concerns about the fate of the 2005 peace agreement that ended a 20-year civil war. Derek Kilner has more from Nairobi.
Since December, several clashes near the contested Abyei area have broken out between troops from the Sudan People's Liberation Movement, the former rebels who now govern Sudan's semi-autonomous southern region, and fighters from the Misseriya, an Arab cattle-herding tribe.
Misseriya leaders have complained that SPLM troops are blocking their grazing paths. SPLM officials say the Misseriya are being mobilized by the northern government in Khartoum, in an attempt to obstruct the implementation of the north-south peace deal.
The status of Abyei, which holds a good portion of Sudan's oil reserves, has long been one of the most contentious issues in the north-south peace process.
The 2005 Comprehensive Peace Agreement called for Abyei's residents to vote in 2011 on whether to remain part of northern Sudan or to join the south. At the same time, the southern region is set to vote on whether to secede from the north. If Abyei votes to join the south, and the south votes to secede, then Khartoum would lose Abyei and the oil sitting under it.
The area is inhabited primarily by members of the Ngok Dinka tribe, who have been strong supporters of the SPLM. But the area's land is also used for grazing by the Misseriya, who have traditionally identified with the north.
The Misseriya were among the tribes armed by Khartoum to fight against the SPLM during the civil war, in much the same way as the janjaweed were armed in Darfur. While the Misseriya community has its differences with the National Congress Party in Khartoum, and while there have been some indications of growing sympathy for the SPLM among the Misseriya, the group is still seen as identifying with the North.
And Khartoum has attempted to count the Misseriya as residents of Abyei, believing they will vote to remain part of the north.
Mariam Jooma, a researcher at South Africa's Institute for Security Studies, says the Misseriya's local concerns over access to grazing land have been caught up in the broader north-south conflict.
"The Misseriya are not like these direct puppets of Khartoum," said Jooma. "But the disaffection of not being able to access particular resources can be manipulated by Khartoum."
The 2005 agreement left the boundaries of Abyei undecided, but established a commission to rule on the matter. The commission's ruling was meant to be final, but Khartoum has refused to accept it.
Frustration with the lack of progress on Abyei was one of the main reasons the SPLM withdrew its ministers from the power-sharing national government in October. The ministers rejoined the government in December, John Duku, the SPLM's representative in Nairobi, says the recent fighting in Abyei is evidence that Khartoum is still obstructing the peace agreement, including preparations for a national census.
"Their intention is to undermine the implementation of the CPA. We have a very important benchmark ,which we must accomplish before the end of the year, that is the census," said Duku. "Now this insecurity will make it difficult to undertake the census in this area because the population is displaced and people are moving around."
The census is a necessary first-step before national elections can be held next year.
The counting was supposed to begin in July of last year, but has been repeatedly postponed. It is now scheduled for April, but any further delays will run into the rainy season in southern Sudan, during which access to much of the region is extremely difficult. The SPLM is concerned that the north could undercount the south's population.
Researcher Douglas Johnson, who was a member of the Abyei Boundary Commission and who has more recently advised the southern Sudanese government, says that given the limited time frame for implementing the peace agreement's provisions, delaying the process amounts to obstructing it.
"I think that you have to regard that as well as what is happening in Abyei as possibly the attempt at least of one faction of the National Congress Party in Khartoum to see if they can hold on to and claw back territory along the North-South border so that come 2011 they can say, yes, the south you can go but we will hang on to those areas we occupy and it will be a very much truncated south that eventually secedes," said Johnson.
But analysts say the south would be unlikely to accept such a scenario, which could well mean a return to war.
In the meantime, with troops from both the north and the south deployed in large numbers in the area, and with the prospect of further clashes between the SPLM and Misseriya, as well as the possibility of conflict spilling over from Darfur to the West, there is a danger that a return to conflict could come even sooner.