Rebels attacked an army checkpoint in Sudan's war-torn border state of South Kordofan, killing an NGO worker and 12 Sudanese soldiers, a UN source said. Armed rebels from the SPLM-North attacked the checkpoint in the Kurgul area, around 35 kilometres (20 miles) south of Deleng, reportedy killing 12 Sudanese soldiers at around 0530 GMT, said the source, requesting anonymity.