Sudan's South Kordofan hit by 'new wave of bombings'
Sudan's military has bombed its volatile South Kordofan region, despite a peace deal to end the conflict, the UN says.
It said heavy bombing and gunfire were heard on Monday around the region's main town, Kadugli.
South Kordofan borders South Sudan, which became independent on Saturday.
About 70,000 people fled bombings in South Kordofan last month, as Khartoum was accused of ethnic cleansing ahead of the south's independence.
The BBC's James Copnall in the capital, Khartoum, says it is very difficult to get accurate information about South Kordofan because journalists and diplomats are barred from the region, and humanitarian workers are generally restricted to Kadugli and major towns.
The conflict began in early June, when there was an attempt to disarm fighters from the Nuba ethnic group in South Kordofan.
They fought alongside the southern Sudanese during the long civil 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 they achieved more rights.
Mr Bashir said peace with South Sudan was conditional on mutual respect of borders and non-interference in each other's affairs.
Khartoum accuses the Nuba fighters of trying to destabilise South Kordofan.
The two sides agreed last month, in a deal brokered by the African Union, to integrate pro-south fighters into the national army or disarm them through dialogue.
Our reporters says the resurgence of conflict shows a ceasefire is still not in place and the war may continue for some time in South Kordofan.
The UN has no confirmed reports of casualties from the clashes, he says.
Meanwhile, an official in Khartoum's ruling party, Gudbi-Al Mahadi, 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 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 in Darfur.
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.