KHARTOUM (AFP) - Fighting erupted on Sunday in South Kordofan, Sudans volatile oil-producing border state, a UN spokeswoman said, where the north is pressuring the Sudan Peoples Liberation Army to disarm. The former southern rebels said the fighting began when a group within the northern army refused to disarm the SPLA troops, a claim the army denied. The United Nations mission in Sudan confirmed the clashes but was unable to say who the fighting was between. There were two attacks. One happened in Kadugli town itself, where a police station was attacked last night (Saturday) by unknown gunmen, UNMIS spokeswoman Hua Jiang told AFP, adding that there was no information on casualties.