Sudan: Kordofan conflict catches thousands, says AU
The African Union says it is deeply concerned about the humanitarian situation in Sudan's Southern Kordofan.
The state, which borders the south of Sudan, has been the site of fierce clashes in the last two weeks.
South Sudan is due to split from the north next month, but Southern Kordofan is in the north of the country.
The African Union (AU) says hundreds of thousands of civilians have been displaced because of fighting in the state, including aerial bombardment.
The clashes are between rebels from the Nuba mountains, and the north's armed forces.
Many Nuba fought on the side of the southern army which won independence for South Sudan, and they largely voted against the north's governing party in recent state elections.
The AU also said allegations of human rights abuses should be investigated.
Khartoum has been accused of "ethnically cleansing" the Nuba, who define themselves as African rather than Arab, making them a minority in northern Sudan.
The AU called for an immediate end to the fighting.
Talks are continuing in the Ethiopian capital, Addis Ababa.
On Monday, northern and southern Sudan agreed to a security solution for the disputed border region of Abyei, which borders South Kordofan.
The northern armed forces took control of the town last month.
They will withdraw, to be replaced by Ethiopian peacekeepers, although a detailed timetable has not yet been set out.
However, there is still no agreement on whether Abyei should be part of Sudan or South Sudan, which will become Africa's newest nation on 9 July.
Both Sudan and the South are reliant on their oil revenues, which account for 98% of South Sudan's budget. But the two countries cannot agree how to divide the oil wealth of the former united state. Some 75% of the oil lies in the South but all the pipelines run north. It is feared that disputes over oil could lead the two neighbours to return to war.
Although they were united for many years, the two Sudans were always very different. The great divide is visible even from space, as this Nasa satellite image shows. The northern states are a blanket of desert, broken only by the fertile Nile corridor. South Sudan is covered by green swathes of grassland, swamps and tropical forest.
Sudan's arid north is mainly home to Arabic-speaking Muslims. But in South Sudan there is no dominant culture. The Dinkas and the Nuers are the largest of more than 200 ethnic groups, each with its own languages and traditional beliefs, alongside Christianity and Islam.
The health inequalities in Sudan are illustrated by infant mortality rates. In South Sudan, one in 10 children die before their first birthday. Whereas in the more developed northern states, such as Gezira and White Nile, half of those children would be expected to survive.
The gulf in water resources between north and south is stark. In Khartoum, River Nile, and Gezira states, two-thirds of people have access to piped drinking water and pit latrines. In the south, boreholes and unprotected wells are the main drinking sources. More than 80% of southerners have no toilet facilities whatsoever.
Throughout the two Sudans, access to primary school education is strongly linked to household earnings. In the poorest parts of the south, less than 1% of children finish primary school. Whereas in the wealthier north, up to 50% of children complete primary level education.
Conflict and poverty are the main causes of food insecurity in both countries. In Sudan, many of the residents of war-affected Darfur and the border states of Blue Nile and South Kordofan, depend on food aid. The UN said about 2.8m people in South Sudan would require food aid in 2013. The northern states tend to be wealthier, more urbanised and less reliant on agriculture.