Sudan's South Kordofan fighting: UN warns of war crimes
A UN report has warned that war crimes may have been committed in Sudan's South Kordofan region.
The report, leaked to the BBC, said both government and rebel forces were guilty of atrocities but the army's actions were "especially egregious".
It called for a special investigation into the conflict, which has displaced about 70,000 people.
Sudan's government says it is responding to rebel attacks in the region which borders South Sudan.
The BBC's James Copnall in the capital, Khartoum, says the report refers to summary executions, aerial bombardments and the shelling of neighbourhoods.
One eyewitness told UN investigators that he had seen 150 bodies at an army barracks in South Kordofan.
The report said the UN Security Council should establish a commission of inquiry to investigate the allegations, possibly with the help of the International Criminal Court.
If the allegations were true, they would amount to war crimes and crimes against humanity, the report said.
A government spokesman rejected the allegations, saying the army was trying to achieve stability in South Kordofan.
He said the region's rebels - not the army - had directed their weapons at civilians.
Last week, the Satellite Sentinel project, a campaign group set up by Hollywood star George Clooney, said it had visual evidence of three mass graves in South Kordofan.
Our reporter says the findings of the UN investigators will increase pressure on President Omar al-Bashir and his government.
The ICC has already issued an arrest warrant for Mr Bashir for alleged genocide and crimes against humanity during the separate eight-year conflict in Sudan's Darfur region.
There is also an arrest warrant for Ahmed Haroun, a former Darfur governor who is now South Kordofan's governor.
Many people in South Kordofan, especially residents of the Nuba mountains, fought with southern rebels during the two decade north-south war but now find themselves in the north.
The two sides agreed last month, in a deal brokered by the African Union, to integrate the pro-southern Nuba fighters into the national army or disarm them voluntarily.
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.