Sudan's South Kordofan fighting: 'Mass graves found'
Satellite images show mass graves following recent fighting in Sudan, a campaign group set up by Hollywood star George Clooney says.
Eyewitnesses who spoke to the group said soldiers had systematically massacred civilians in South Kordofan.
Fighting began in the state last month, between rebels from the Nuba mountains and the Sudanese armed forces.
A Sudanese military spokesman denied allegations that civilians had been killed.
South Kordofan borders South Sudan, which last week became an independent state.
Some 70,000 people have fled the recent fighting there.
The Satellite Sentinel project says the satellite images show three apparent mass graves.
An eyewitness told the group that about 100 bodies were taken to a site near a school in the village of Tilo, not far from the state capital, Kadugli, after fighting last month.
"The DigitalGlobe satellite images contain many of the details and hallmarks of the mass atrocities described by at least five eyewitnesses to the alleged killings," said Nathaniel A Raymond, of the Harvard Humanitarian Initiative, which analyses the project's images.
Although a peace deal was signed recently, a UN report this week said bombing and fighting was continuing in South Kordofan.
Sudan's ruling National Congress Party spokesman Rabie A Atti strongly denied the claims, saying they were designed to discredit the government.
"People can go there and visit the area and see what is the actual reality," the AP news agency quotes him as saying.
The BBC's James Copnall in Sudan's capital, Khartoum, reports that it is extremely difficult to get accurate information, as journalists and diplomats are barred from the region and the UN faces restrictions on its movement.
The Satellite Sentinel project says the apparent massacre took place in the town of Kadugli, in South Kordofan.
People who spoke to the campaign group said forces aligned with Khartoum are systematically killing civilians believed to be opposed to the government.
The US President Barack Obama has already expressed his concern at reports of attacks in South Kordofan based on ethnicity.
Khartoum denies the allegations, and says it is fighting a legitimate war of self-defence against insurgents.
Many residents of the Nuba mountains fought with southern rebels during the two decade north-south war but now find themselves in the north.
South Sudan's President Salva Kiir said he would work with Sudan's President Omar al-Bashir to ensure their rights were respected.
Mr Bashir has recognised South Sudan but says peace with Sudan's new neighbour was conditional on mutual respect of borders and non-interference in each other's affairs.
The two sides agreed last month, in a deal brokered by the African Union, to integrate the Nuba fighters into the national army or disarm them voluntarily.
An official in Khartoum's ruling party, Qutbi al-Mahdi, has accused aid agencies of giving logistical support to the rebels, the pro-government Sudanese Media Centre (SMC) reports.
He warned the agencies that they risked "legal penalties" and expulsion, SMC said.
In 2009, Sudan expelled 10 humanitarian organisations from the western region Darfur, accusing them of collaborating with the International Criminal Court (ICC).
The ICC has issued an arrest warrant for Mr Bashir for alleged genocide and crimes against humanity during Darfur's eight-year conflict.
There is also an arrest warrant for Ahmed Haroun, a former Darfur governor who is now South Kordofan's governor.
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.
The spokesman for the Sudanese Armed Forces, Colonel Khalid Sawarmi, told the BBC this was not true, and civilians hadn't been killed inside Kadugli.