North Korea may make an “important” announcement Monday, amid rumors that reclusive leader Kim Jong-il has fallen seriously ill, a Japanese media report said Sunday. In South Korea, officials shrugged off the report, saying there was no proof of any planned announcement. Sources told the country's Yonhap news agency that they had not detected any unusual movements in the North. Japan's Sankei Shimbun newspaper, quoting an unnamed defense ministry source, said Sunday that an “announcement of important information will be made on October 20.” “It is not clear whether the set of information is related to the health of Kim,” the conservative newspaper said. North Korea could move to ban foreigners from entering the country from Monday, the Sankei said, quoting several unnamed sources. The defense ministry source told the newspaper that no major military movements have been detected in North Korea, which Kim has ruled since the mid-1990s, assuming power following the death of his father Kim Il-Sung. The Japanese foreign ministry declined to comment on the Sankei report, which cited unsubstantiated rumours that the secretive North could announce Kim's death or a change in leadership following a coup. Reports of Kim's illness surfaced after he failed to appear at the country's 60th anniversary parade on September 9. South Korean officials have said he underwent brain surgery following a stroke around mid-August. North Korean state television a week ago aired photographs of the 66-year-old Kim inspecting a women's artillery base, although a US official doubted that the images were recent. Some reports said Kim has suffered partial paralysis. The Sankei report came one day after Japan's Yomiuri Shimbun said North Korea had ordered its diplomats overseas to prepare for an “important announcement” that may be related to Kim's health. The Yomiuri, quoting several unnamed sources familiar with North Korean issues, said Saturday that Pyongyang's diplomats had been ordered not to travel ahead of the announcement, which was expected in a few days. The Sankei quoted another unnamed source as saying: “It is clear that North Korea is alarmed about the inflow of information and contact with the outside world. It may be a measure to tighten up internal affairs.”