* Burning, looting reported in state capital Kadugli
* Tens of thousands believed to have fled
* South Sudan due to secede in July
KHARTOUM, June 13 (Reuters) - More than 53,000 people have fled fighting, including bombardments and artillery shelling, in Sudan’s Southern Kordofan border state, the United Nations said.
The northern army has been battling southern-aligned troops in the oil state since June 5. Humanitarian organisations fear a mounting death toll although few casualties have been confirmed so far.
South Sudan is due to become an independent state on July 9.
Southern Kordofan is a northern state but analysts say it is home to thousands of fighters who sided against Khartoum during the civil war.
The U.N. Office for the Coordination of Humanitarian Affairs (OCHA) said its partners had reported the “burning of tukuls, looting of humanitarian assets and emergency relief stocks, and the presence of land mines” in the state capital Kadugli.
“As the security situation shows no sign of improvement, the number of displaced civilian populations who are in urgent need of relief assistance is increasing with unconfirmed reports of more than 53,000 people displaced,” it said in a statement.
The United Nations previously estimated between 30,000 and 40,000 may have fled Kadugli alone.
Officials from the northern and southern ruling parties have traded blame over who started the fighting in Southern Kordofan, which has since spread across the state and into the poorly-defined north-south border region.
Leaders in the northern branch of the south’s dominant Sudan Peoples’ Liberation Movement (SPLM) said it began when the northern army tried to disarm fighters. The northern army has blamed southern-aligned armed groups for provoking the clashes.
The north’s ruling National Congress Party on Sunday warned the south against supporting what it describes as a “rebellion” in the state.
The southern military says the fighters in Southern Kordofan are no longer part of its army, despite sharing a name and historical ties.
Southerners voted to secede in a January referendum, the culmination of a 2005 peace deal that ended decades of north-south civil war. That conflict cost some 2 million lives. (Reporting by Alex Dziadosz and Jeremy Clarke in Juna; Writing by Alex Dziadosz; Editing by Janet Lawrence)