By Khalid Abdelaziz and Hereward Holland
KHARTOUM/JUBA (Reuters) - Sudan's army and forces aligned to South Sudan clashed Friday in a Sudanese state on the border with the newly independent south, prompting what witnesses said was an exodus of people from the state capital.
Sudan's Blue Nile state is home to many supporters of the south's dominant Sudan People's Liberation Movement (SPLM). Khartoum has previously threatened to disarm southern-aligned fighters in Blue Nile state.
Witnesses contacted by telephone said many residents fled al-Damazin, the state capital where clashes erupted, by vehicle, horse, donkey or foot. Some said thousands fled. An SPLM official said there was a "massive" movement of people.
There was no immediate official comment on any exodus. U.N. Secretary-General Ban Ki-moon voiced alarm at violence.
Ban is "deeply concerned about the deterioration of the security situation in Southern Kordofan and the eruption of fighting in Blue Nile State," a U.N. statement said.
"The Secretary-General urges the parties to immediately cease all hostilities and allow access to the humanitarian agencies to all affected areas," it added.
U.N. peacekeepers who used to patrol the north-south border are pulling out because Khartoum withdrew its consent. The mandate for the 10,000-strong blue-helmeted UNMIS force, which is separate from a joint U.N.-African Union force in Darfur, lapsed on July 9 and has not been renewed.
Sudan's government announced a state of emergency in Blue Nile and said it was appointing a military ruler for the state, the official news agency SUNA. It said it had dismissed the state governor, who is a member of the SPLM's northern branch.
AIR RAID
The SPLM condemned the decision to fire the governor.
"The Sudanese army started the attack on our positions," Malik Agar, Blue Nile governor told Reuters by telephone before the decision to relieve him of his post was announced.
He accused Khartoum of planning the attack because it moved soldiers and 12 tanks to al-Damazin shortly before the clashes.
Agar also said the Sudanese government launched air raids on an area around the Blue Nile town of Kormok, saying a woman and child were killed. Another SPLM official said four had been killed in aerial attacks, including two women.
Sudanese army spokesman Al-Sowarmy Khalid Saad told Reuters that SPLM forces attacked Sudan's army late Thursday in and around al-Damazin. The army responded and was now in control.
There was no immediate government comment on any air raid.
Similar clashes and mutual accusations about who was to blame have led to an escalation in violence in South Kordofan, another state in the north that is on the southern border. Thousands previously fled violence in another hotspot, Abyei.
Agar earlier told SUNA clashes erupted between the SPLM-aligned forces at the entrance of al-Damazin and the Sudanese army forces during the night of Thursday to Friday and spread.
South Sudan split from the rest of the country in July after a referendum on secession, part of the 2005 peace deal that ended decades of conflict between north and south. The separation was relatively smooth but tensions simmer.
Under the 2005 deal, residents of Blue Nile and South Kordofan were offered "popular consultations" to determine ties to Khartoum. These have not been completed.
"(Khartoum's) objective is to knock out the SPLM-North before they become a serious military force," Chris Phillips from the Economist Intelligence Unit told Reuters by telephone.
He said Khartoum might see the group as a new secessionist threat to Sudan, which also faces a rebellion in Darfur.
Yasir Arman, secretary-general of the SPLM's northern branch, said in a statement that the Sudanese army attacked the residence of Al-Jundi Suleiman, commander of the joint integrated units in Blue Nile, and then other areas.
"The offensive was later intensified to include all SPLA (Sudan People's Liberation Army) positions," he said.
On the decision to sack the governor, Arman told Reuters: "This is a political and military coup against the constitution, the (2005 peace deal) and the will of the people who brought Malik Agar into government."
He also said late Friday there was a "massive" movement of people fleeing fighting to the countryside but was not able to give numbers. He called for the international community to impose a 'no-fly' zone to stop air raids in the area.
Arman said Sudan was creating a new conflict with people's stretching from Darfur to Blue Nile along its southern border.
In a statement carried by SUNA, the Sudanese government said it had ordered the SPLM to hand over those involved. It accused SPLM loyalists of attacking Sudanese army soldiers who were part of the integrated forces in Blue Nile.
Fouad Hikmat of the International Crisis Group said Sudan's ruling party believed the SPLM in the north was "a threat for them politically, not just militarily and this could be a vanguard to mobilise the new South of the North of Sudan."
One observer who has worked in Blue Nile and the south said southern-aligned forces in Blue Nile were indigenous to the region and, unlike southern army units that had to move south after secession, these units could not be moved out.
(Additional reporting by Louis Charbonneau in New York; Writing by Edmund Blair; Editing by David Stamp and Cynthia Osterman)
