Sudanese police used batons on Saturday to disperse about 30 demonstrators who were calling for the independence of the country's south during a pro-unity rally in Khartoum.
Some 3,000 people had gathered near the presidential palace for a government-organized rally in support of unity, three months before a referendum on independence which could split Africa’s largest country in two.
A group of southerners dressed in orange T-shirts with the slogan "the referendum is our golden opportunity for independence" chanted "No to Unity. Yes to secession."
Angry pro-unity demonstrators pushed the southerners out of the rally, forcing riot police to intervene.
Police beat the southern demonstrators with long wooden sticks, as did other members of the crowd.
"I am for the unity of Sudan, not for secession, we are one country," said Abdelbakir Mohammed Omar, a Khartoum resident.
"We Sudanese are already suffering. And they (foreigners) want to make us suffer more. Let them leave us alone," said an angry Adbelmajid, accusing the West particularly the United States, of encouraging south Sudanese secession.
The rally came as U.N. Security Council delegation headed by U.S. ambassador Susan Rice was wrapping up a four-day visit to Sudan.
Relations are tense between north and south Sudan ahead of the crucial referendum on January 9 when southerners will vote on whether they want to become independent or remain part of a united Sudan.
This week Sudan’s military accused the army of the semi-autonomous south of crossing a disputed border, warning the "violation" could derail the referendum.
"The redeployment of the SPLA (southern army) into the (northern) White Nile state violates the peace accord and threatens the referendum," parliament speaker Ahmed Ibrahim al-Tahir, told the crowds on Saturday.
Peacekeeper protestA diplomat with the delegation told Reuters earlier that Salva Kiir, president of semi-autonomous south, had made the peacekeeper request at a meeting in the southern capital Juba on Wednesday.
"Salva Kiir asked for U.N peacekeepers to be deployed along the border between the north and the south," the diplomat said on condition of anonymity.
The diplomat said the request would be considered but that no promises had been made. Another diplomat with delegation said a deployment was not something explicitly called for in the 2005 Comprehensive Peace Agreement (CPA) and would therefore require some "adjustments".
The U.N. has 10,000 peacekeepers stationed in Sudan, not counting its joint mission with the African Union in Darfur, most of them in the south and three former civil war battleground areas along the border.
Southerners, embittered by the conflict and perceived northern exploitation, are widely expected to choose secession. Khartoum wants to keep Africa’s largest country united.
Troops from both sides have clashed since the accord, most recently in the contested Abyei oil region. The two sides have also accused each other of building up troops near their shared border as the referendum approaches.