KHARTOUM (AFP) - Fighting between elements of Sudan's northern and southern armies in Kadugli, capital of volatile South Kordofan state, has killed six people and forced UN agencies to suspend operations there, UN sources said on Tuesday. "There has been continued gunshots heard in the town itself today... The fighting is between elements from the SAF (Sudanese Armed Forces -- the northern army) and the SPLA (Sudan People's Liberation Army -- the southern army)," Hua Jiang, spokeswoman for the United Nations Mission in Sudan (UNMIS), told AFP. "At one of the hospitals we visited, we saw six dead bodies, four of whom were government of Sudan police, and the other two civilians... Earlier we saw about 3,000 people taking refuge at the Kadugli police hospital," she added. A UN source in Kadugli said that, since Monday, all UN agencies had suspended their operations in the state capital, where the United Nations has a large presence, and had withdrawn to the UNMIS peacekeeping compound near the airport. "Now the situation is a little bit calm, but at any time it can flare up," the source said, speaking on condition of anonymity.