A South Korean government official visited North Korea on Friday for the first time since Seoul cut most ties with Pyongyang 18 months ago, an official said. Cho Joong-Hoon, head of the unification ministry\'s humanitarian assistance department, is travelling with four representatives of an NGO group to ensure private food aid is properly distributed, a ministry spokesman said. It was the first such visit since Seoul severed most links in May 2010 after accusing its neighbour of sinking a South Korean warship two months earlier, the spokesman said. The visitors will inspect three facilities including a children\'s day care centre in the northwestern city of Jongju to ensure that 300 tonnes of flour aid supplied by the NGO reaches the intended recipients.     The ministry by law must authorise all contacts with the North including private aid shipments. \"The government has been persistent in making efforts to enhance transparency in distribution of food aid in the North,\" the spokesman said. Relations hit rock-bottom in November last year when the North shelled a South Korean border island and killed four people. In recent weeks there have been some signs of easing relations. The South has permitted private food aid and some non-official cross-border visits. But the North\'s military threatened Thursday to turn Seoul\'s presidential office into \"a sea of fire\" in an angry response to a South Korean military exercise near the tense sea border. Agence France-Presse