Two prominent South Koreans have crossed the border into the North to pay their respects to the late leader of the secretive state, Kim Jong-il. Former South Korean First Lady Lee Hee-ho and Hyundai firm head Hyun Jung-Eun will spend two days in Pyongyang. Seoul has banned most South Koreans from visiting the North to express condolences, angering its neighbour. Separately, the North\'s main newspaper has called new leader Kim Jong-un the head of the ruling party\'s key body. The Rodong Sinmun paper described Kim Jong-il\'s son as the head of the Workers\' Party Central Committee, meaning that he was now in control of one of the country\'s highest decision-making bodies as he was preparing for the transfer of power. North Korea is trying to carry on the world\'s only Communist family dynasty. Kim Jong-il, who inherited power from his father in 1994, died on 17 December - reportedly after suffering a heart attack. His son is seen by many analysts as a political novice, thought to be in his late 20s. Mrs Lee, 89, and Mrs Hyu, 56, crossed the border into the North on Monday. \"I hope that our visit to the North will help improve South-North relations,\" the former first lady was quoted as saying by the South\'s Yonhap news agency. The two women have been given special permission to pay their respects in person, because both families have received personal condolences from the North in the past, the BBC\'s Lucy Williamson in Seoul reports. Both have also strong ties to the North, our correspondent adds. Former President Kim Dae-jung held the first inter-Korea summit with Kim Jong-il in 2000, while Hyundai has been a key economic investor into Pyongyang. But Seoul has stressed that they are visiting in a purely personal capacity. The two women are expected to return home on Tuesday - a day before the state funeral of Kim Jong-il. The North has condemned Seoul\'s ban on cross-border condolence visits by South Koreans, warning that this would have \"grave implications\" for bilateral relations.