20 May 2012 Last updated at 09:57 ET

Sudan releases four foreigner seized in disputed area

The freed men are reportedly de-mining specialists

Sudan has freed four foreigners detained last month near the border with South Sudan, officials say.

Former South African President Thabo Mbeki, who mediated between the two states, thanked Sudan for the release.

The four - from the UK, Norway, South Africa and South Sudan - were held in the disputed area, scene of recent clashes between Sudan and South Sudan.

Sudan had said the men were suspected of aiding South Sudan - a charge rejected by the South.

War debris

The government in Khartoum on Thursday confirmed the release of the four foreigners.

Sudanese Defence Minister Abdelrahim Mohammed Hussein said: "We release them to President Mbeki."

The freed men then got into a vehicle, which was part of Mr Mbeki's motorcade, according to the AFP news agency.

The foreigners - whose names have not been released - were detained on 28 April.

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

• South Sudan refugees flown home

Reports say they are de-mining specialists and were collecting war debris in the Heglig oilfield.

A United Nations spokesman in South Sudan was quoted at the time as saying that a staff member was among the group seized by Sudanese solider.

Mr Mbeki has been in Khartoum to try to bring Sudan and South Sudan back to the negotiating table following the recent clashes.

The fighting began in April when Heglig was occupied by forces from South Sudan.

They left about a week ago, after holding the area for 10 days.

The BBC's James Copnall says tension is still extremely high, and Sudan has been accused of carrying out a number of air raids on South Sudan this week. It denies the charges.

South Sudan became independent from Sudan after a civil war that lasted two decades and in which an estimated 1.5m people were killed.

Sudan: A country divided

• Oil fields
• Geography
• Ethnic groups
• Infant mortality
• Water & sanitation
• Education
• Food insecurity

Show regions

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. The residents of war-affected Darfur and South Sudan are still greatly dependent on food aid. Far more than in northern states, which tend to be wealthier, more urbanised and less reliant on agriculture.