JUBA (Reuters) - Seventeen people have been killed in fighting between Sudan's army and rebels aligned to South Sudan in a Sudanese state on the border with the newly independent south, the official news agency SUNA said on Saturday.
Up to 3,000 people fled armed clashes in the region, the United Nations refugee agency (UNHCR) reported, calling for an immediate halt to the fighting to prevent a humanitarian crisis.
Analysts say Sudan's government in Khartoum is trying to strike against the rebels in South Kordofan and Blue Nile states before they become a serious secessionist threat.
South Sudan seceded from Sudan -- at the time Africa's largest country -- in July, six years after a cease-fire that ended decades of civil war between north and south. South Sudan denies Khartoum's accusations that it is supporting the rebels.
SUNA said 17 people were killed and 14 wounded in the fighting in South Kordofan, but gave no further details.
Qamar Dalman, an official with the South Kordofan branch of South Sudan's dominant party, the Sudan People's Liberation Movement (SPLM), told Reuters that about 14 government soldiers were killed during the clashes in South Kordofan.
"All the civilians had fled the area and the ones who were killed were from the government, not civilians," Dalman told Reuters by telephone.
In Blue Nile, ground clashes and bombardments by Sudanese aircraft Friday forced many people to flee, said Peter de Clerq, a spokesman for the U.N. refugee agency.
"Between 2,500 and 3,000 people crossed into Ethiopia yesterday morning but the number will have gone up since then," he said. "In (the town of) al-Damazin there was serious fighting yesterday but we're not sure how many people have left. We understand that significant numbers of people are trying to leave al-Damazin."
U.N. APPEAL
UNHCR chief Antnio Guterres appealed for an immediate halt to the hostilities amid reports of escalating displacement.
"We need, at all costs, to stop yet one more refugee crisis in a region of the world that has been witnessing in recent months so much suffering," said Guterres in a statement after visiting nearby conflict- and famine-ridden Somalia.
Yasir Arman, secretary-general of the SPLM's northern branch, said eight people had been killed in al-Damazin including two women, a child and four SPLM-N members.
"Many SPLM-N were arrested in al-Damazin and we're not sure of their fate. We're worried because all those who were arrested in South Kordofan were slaughtered by security agents," he said.
Last week international rights groups said witnesses saw Sudanese government soldiers and militia shoot people in the streets and carrying out both house-to-house searches and stops at checkpoints using lists of names of SPLM supporters in the South Kordofan state capital Kadugli and other areas.
"We are having wider political consultations with political forces inside and outside the country. The aim is to create a political and civil society alliance to bring democracy," said Arman. But some analysts believe the SPLM-N is now politically isolated and needs partners in order to sustain their rebellion.
" are now a rebel group. The only way for them to survive is through insurgency and rebellion until they can negotiate a political settlement," Fouad Hikmat of the International Crisis Group told Reuters.
"They need to sustain this rebellion and therefore need partners in the neighbourhood -- South Sudan and Ethiopia."
The Sudan government declared a state of emergency in Blue state Friday and said it was replacing elected governor Malik Agar with a military ruler, SUNA said.
(Reporting by Hereward Holland in Juba and Khalid Abdelaziz in Khartoum; Editing by Mark Heinrich)
