Dozens of people were killed in clashes between two Arab tribes in Sudan's troubled East Darfur state on Monday, a politician told AFP.

Fighting broke out between the Rezeigat and Maaliya groups around the Abu Karinka area of East Darfur state, the latest in a series of bloody ethnic and tribal conflicts in the region.

Over 300,000 South Sudanese civilians are without "life-saving aid" in the northern battleground state of Unity, the United Nations said Monday, as it and aid agencies pulled out due to heavy fighting.

The violence is some of the worst in the country's 17-month-old civil war, as government forces push south from the state capital Bentiu into an opposition zone around the town of Leer, home to some of the country's once lucrative oil fields.

Sudanese anti-aircraft crews shot down an "aerial target" near Khartoum's twin city of Omdurman, a military spokesman said on Wednesday, after witnesses reported hearing explosions in the area.

An air base detected the target around 10:45 pm (1945 GMT) on Tuesday flying at low altitude over Omdurman's Wadi Sayidna military area, checked there were no civilian planes nearby and shot it down, military spokesman Colonel Al-Sawarmy Khaled Saad said in a statement.

Sudan denied a UN request for the emergency evacuation of a wounded Ethiopian peacekeeper who later died of his injuries in Darfur, the UN chief said Monday.

Secretary General Ban Ki-moon said he "deeply regrets" that Khartoum turned down the request on Sunday and offered condolences to the peacekeeper's family.

He may have easily secured another five years in power on Monday, but President Omar al-Bashir still faces major challenges in solving Sudan's economic woes and ending its international isolation.

Bashir, who won more than 94 percent of the vote, is also wanted by the International Criminal Court over war crimes in the western region of Darfur, curtailing his ability to travel abroad freely.

Sudan's President Omar al-Bashir was elected to another five years in office, results showed Monday, despite international war crimes charges and a vote marred by low turnout and an opposition boycott.

Bashir, 71, took more than 94 percent of the vote in the election held earlier this month, the electoral commission said, prompting the opposition to reject the result as a "joke."

North Korea has increased its "material support" for terrorist organizations and should be placed back on America's list of nations that are state sponsors of terrorism, a report released Monday said.

The Pyongyang regime, at the time under the command of Kim Jong-il, was taken off the list in 2008 under the presidency of George W. Bush, who hoped to engage the reclusive nation in dialogue. 

Sudan's government on Sunday accused peacekeepers in Darfur of killing seven civilians, disputing the UN-African Union mission's version of events in which it said its forces had repelled two attacks by gunmen.

The U.N.-AU Mission in Darfur (UNAMID) had said 40 gunmen fired on a patrol in South Darfur's Kass area on Thursday, before the peacekeepers returned fire and killed four assailants, and another patrol came under fire the next day.

Sudan's military accused Juba of supporting rebels from Darfur after Khartoum's troops clashed with the insurgents in part of the war-torn region near the border between the two countries Sunday.

The army said the Justice and Equality Movement -- one of several groups battling Sudanese forces in Darfur since 2003 -- used South Sudan's Bahr al-Ghazal region as a base to enter neighboring Darfur on Sunday, where the two sides clashed.

South Sudan's warring leaders must strike a compromise deal, the European Union's aid chief said Saturday, warning the international community was running out of patience over the country's civil war.

"The war and the blame games must stop, and they must stop now -- it is high time for peace," said EU Commissioner for Humanitarian Aid Christos Stylianides, after travelling to both government and opposition strongholds in the war-torn country to plead with leaders to end fighting.