The United Nations Mission in Sudan says fighting in a north-south border state has spread and the humanitarian crisis there has worsened.

In an interview with VOA Thursday, spokesman Kouider Zerrouk described the security situation in and around the capital of South Kordofan state as “volatile and tense.”

He said fighting between the north's Sudanese Armed Forces and elements of the south's Sudanese People's Liberation Army has spread to towns surrounding the capital, Kadugli. Sporadic gunfire was reported on Thursday in the towns of Kauda, Talodi and Dilling.

The spokesman said thousands of people have left their homes with few possessions, many fleeing to a U.N. mission compound in Kadugli and into the bush.

Zerrouk said wide-scale looting has taken place in towns left virtually deserted, including at U.N. facilities and the offices of aid agencies.

Escalating violence in South Kordofan and the disputed Abyei region have raised concerns that a new civil war may break out in Sudan.

The south will declare independence from the north on July 9, but the two sides remain split on several key issues, particularly the future of oil-rich Abyei.

North Sudanese forces seized control of Abyei in May.

South Sudan voted to split from the north in a January referendum. The referendum was part of a 2005 peace agreement that ended a 21-year civil war between the north and south.