World News Today: Sudan: '60,000 flee air raids'

Residents of Kadugli gathered outside UN sector headquarters waiting to collect water after fleeing fighting in Kadugli town, South Kordofan

The UN says aid efforts in South Kordofan are being hampered

Some 60,000 people have fled bombing in Sudan's South Kordofan region near the north-south border, the UN says.

Northern forces are accused of targeting the area's pro-southern groups, as oil-rich South Sudan prepares for independence next month.

US President Barak Obama has called for a ceasefire following the upsurge of fighting, to prevent a return to the two-decade north-south civil war.

Khartoum was pursuing a genocidal campaign in South Kordofan, the Sudan Democracy First Group said, AFP news agency reports.

But a spokesman for the Sudanese embassy in London, Ibrahim Mubarak, said pro-south militias were responsible for the conflict.

"They are not disciplined. They attacked UN forces and Sudanese army forces and instigated the whole situation," he told the BBC's Network Africa programme.

The UN humanitarian agency, Ocha, said 11 areas were affected by the violence, forcing many people to hide in mountainous areas.

"There is a growing sense of panic among some of the displaced populations who find themselves trapped by the ongoing violence and ethnic fault lines," it added.

Sudanese fighter jets dropped 11 bombs in the areas of Kadugli and Kauda early on Wednesday, apparently targeting an airfield, a UN observer mission spokesman in Sudan, Kouider Zerrouk, told AFP.

The UN had appealed to the Sudanese government to allow planes to land at the main airport in Kadugli so that it could carry out relief efforts.

Roadblocks manned by militia were preventing aid reaching thousands of people in need, the UN said.

In a recorded audio message, Mr Obama said both the north and south should "live up to their responsibilities" by ending the conflict.

"The government of Sudan must prevent a further escalation of this crisis by ceasing its military actions immediately, including aerial bombardments, forced displacements and campaigns of intimidation," he added.

Southern Information Minister Barnaba Marial Benjamin welcomed Mr Obama's remarks and said a well-planned disarmament, demobilisation and reintegration programme was needed instead of the current use of force.

Meanwhile, the head of the worldwide Anglican church, Archbishop of Canterbury Rowan Williams, said the unrest was a major threat to the stability of Sudan.

"The humanitarian challenge is already great, and the risk of another Darfur situation, with civilian populations at the mercy of government-supported terror, is a real one," the archbishop said, according to AFP.

The bombing in South Kordofan follows a deal for both sides to withdraw from the nearby disputed town of Abyei.

Clashes over the past month in Abyei and South Kordofan have raised fears of renewed north-south conflict despite a 2005 peace deal which paved the way for the end of decades of war.

Talks on issues about the upcoming split between Sudanese government officials and representatives of the south are continuing following Monday's deal for both sides to withdraw from Abyei.

President Omar al-Bashir and southern leader Salva Kiir agreed that Abyei, claimed by both sides, would be demilitarised, with Ethiopian troops ensuring security.

The north-south war ended with a 2005 peace deal, under which the mainly Christian and animist south held a referendum in January on whether to secede from the largely Arabic-speaking, Muslim north.

Some 99% of voters opted for independence. President Bashir said he would accept the verdict of the south, where most of Sudan's oil fields lie.