UNITED NATIONS - A tangle of mounting military tensions and political disputes poses a new threat to Sudan as Africa's biggest nation heads toward division in less than three months, the UN said Wednesday.
The southern Sudan government, which is to formally declare independence on July 9, faces challenges from insurgents and militias in its own territory, a top UN official warned the Security Council.
A troop buildup around the contested Abyei region on the frontier between the north and south has heightened military tensions between the two sides.
Southern Sudan held a referendum in January in which the population voted massively to break from the north. That vote was part of an accord that ended a civil war in which two million people died.
The euphoria in the south has quickly ended. A rebel attack on a south Sudan army, SPLA, base in Unity State on Tuesday left 20 soldiers dead, according to the army.
"Tensions in the south have risen, particularly conflicts between the SPLA and insurgents and militia" in the south's Jonglei, Upper Nile and Unity states, Atul Khare, a UN assistant secretary general told the Security Council.
"The government of southern Sudan will need to take concrete measures to address ethnic tensions, mismanagement, political and social marginalization, economic development and governance," he added.
Abyei, where the north and south have embarked on what the UN called a "sizeable" military buildup, is a particular concern to the international community. The January referendum was not held in the oil-rich region because the two sides could not agree who could take part.
Scores have been killed in fighting since then between the rival Misseriya and southern Ngok Dinka communities. "Abyei remains a flashpoint that has the potential to further escalate and damage the relationship between the North and South, Khare," Khare said.
The north and south have failed to make major progress on Abyei, drawing up their border, oil revenue sharing, votes in other states near the border with south Sudan and integrating militias into the two armies.
Khare warned that unless quick action is taken the tensions "can quickly undermine progress and threaten to pull the parties back into conflict." He raised doubts that negotiations will be concluded by July 9.
The rebel South Sudan Liberation Army (SSLA) said it had killed "dozens of SPLA," as well as destroying four of its trucks and seizing "several" rocket-propelled grenade launchers, mortars and heavy machine-guns.
But it dismissed as "pure nonsense" claims that the group had itself suffered heavy losses.
"Four of our men were wounded, that was all," insisted rebel spokesman Bol Gatkouth, while also rejecting allegations that the Misseriya had joined the rebels.
Gatkouth accused the governor of Unity state, Taban Deng Gai, of human rights abuses, including the recruitment of child soldiers and the theft of cattle and women from their community because Gadet had turned against the Juba government.
A wave of clashes since January between the SPLA and rebel groups in three southern states has left hundreds dead, souring the mood ahead of independence.
Human Rights Watch said Wednesday that both the army and a rebel group led by Johnson Ulony had committed human rights violations during clashes in Upper Nile state in early March, when more than 60 people died, including women.
The exact number and nature of the casualties is still unknown because the area remains largely off-limits to UN and humanitarian groups, HRW said.
"If the southern Sudan government wants a sustainable peace when it becomes fully independent in July, it should demonstrate its commitment now with a prompt and thorough investigation into human rights violations in Upper Nile," said the rights watchdog's Africa director Daniel Bekele.
SPLA spokesman Aguer insisted the SPLA had not targeted civilians.