Abyei crisis: UN confirms Sudan troop pullout
Sudan has pulled its troops out of the disputed border region of Abyei, according to the UN.
The UN peacekeeping mission in Abyei confirmed the withdrawal took place late on Tuesday evening.
The pullout comes as negotiators from Sudan and South Sudan meet in Ethiopia to begin talks over several disputes.
Abyei is claimed by both Sudan and the South, which became independent in 2011 after a long civil war. Sudan's forces seized Abyei last May.
But a source has told the BBC that the number of police in the area has been increased to about 200, raising fears that some Sudanese soldiers may have simply changed into police uniforms in order to stay.
Either way, the BBC's James Copnall in Khartoum says the presence of Sudanese police is likely to worry the tens of thousands of displaced people who are now considering moving back to Abyei.
Its status was left undecided in the 2005 peace deal between the two sides, and a referendum on the issue has been postponed indefinitely.
Sudanese officials had said the pullout was designed to aid the progress of the peace talks.Mutual distrust
The talks in the Ethiopian capital Addis Ababa are expected to cover several border disputes that have caused friction, including Abyei.
Main disputes between the two Sudans
- The amount the South should pay Sudan to use its oil pipelines
- Demarcating the border
- Both sides claim Abyei
- The rights of each other's citizens now in a foreign country - there are estimated to be 500,000 southerners in Sudan and 80,000 Sudanese in the South
- Each accuses the other of supporting rebel groups on its territory
But the level of distrust between the two sides is considerable, and rapid progress on the many areas of substantial disagreement is unlikely, the BBC's James Copnall in Khartoum reports.
South Sudanese officials have also accused Sudan of carrying out bombing raids in border areas of South Sudan in recent days.
"Today the Sudan armed forces are still bombing in Warguet area," South Sudanese Information Minister Barnaba Marial Benjamin told Reuters as the talks were due to begin.
Sudanese officials denied attacking the South.
There are strong feelings in both countries about Abyei. The Misseriya, a Sudanese group, take their cattle through the region every year.
But the Dinka Ngok, the permanent residents of the area, want Abyei to be part of South Sudan.
But even if from now on the only troops in Abyei are UN peacekeepers, the underlying problem of how to decide its future remains, our correspondent says.Outstanding disputes
In April, cross-border clashes centred on the neighbouring oil-rich region of Heglig brought Sudan and South Sudan close to all-out war.
In the same month, the South's troops occupied Heglig for a week. It said it pulled out in response to international pressure, but Sudan said it reconquered the territory.
The UN Security Council has called on both countries to cease all bombing and cross-border fighting.
Outstanding issues also include disputes over oil revenues and the situation of the estimated half a million South Sudanese still living in Sudan.
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.