GENEVA (AFP) - United Nations chief Ban Ki-moon urged people to remain vigilant and alert about swine flu on Tuesday as the number of cases around the world shot up to almost 10,000. Previous pandemics had shown flu outbreaks could start mild and worsen, Ban said as he addressed the World Health Organisations annual sssembly in Geneva. That is why the world must remain vigilant and alert to the warning signs. The UN health agency said cases had soared by more than 1,000 since Monday with 9,830 infections now in 40 countries, including 79 deaths. One fatality in the United States was still to be confirmed.The WHO has so far resisted pressure to declare a full-fledged swine flu pandemic, but anxiety about the spread of the virus especially in Asia and the Americas is growing. Japan reported 193 swine flu infections Tuesday and closed more than 44,00 schools, colleges and kindergartens for the rest of the week to slow the spread of the virus, officials said. Ban flew in to Geneva late on Monday to attend the WHOs annual assembly and for talks with leaders of some of the worlds biggest pharmaceutical companies on the development of a vaccine. About 30 vaccine makers from 19 industralised and developing countries were invited by the WHO to the discussions which officials said focused on the cost of the vaccine and its availability in the most vulnerable poor countries. The WHO has been weighing up the risks of halting production of the seasonal flu virus to free up production capacity for a swine flu vaccine. An extract of a WHO forecast presented to vaccine makers said it should be possible to produce 4.9 billion doses of a swine flu vaccine in a year, but only if full scale production was launched. The UN health agency is counting on output of 94.3 million doses a week, according to the presentation made to pharmaceutical companies, which was partly seen by AFP. WHO Director General Margaret Chan reiterated that for the moment there was still a need to give priority to seasonal flu vaccine, especially in the southern hemisphere where the winter influenza season is just starting. The Swiss pharmaceutical group Novartis said it had received samples of the new A(H1N1) influenza virus and was waiting for the WHO green light to start making a vaccine. We have received the virus and our researchers have started looking into modifying it so we can begin producing a vaccine, said a spokesman, adding it would take three to four weeks to get production up and running. Vaccine developments will be eagerly watched in world capitals, none more so than in Tokyo where officials are struggling to keep a lid on Japans growing epidemic. Experts warned that infections had probably already spread to other regions including the capital Tokyo, which with almost 36 million people is the worlds most populous urban area and the heart of the Japanese economy. Of course, there is no need to overreact, but authorities and people in the capital should go ahead with their preparation, Nishiyama told AFP. Japans first domestic cases of swine flu were confirmed Saturday in the western cities of Kobe and Osaka, where they spread quickly in and between two high schools that had met for a volleyball tournament. Hundreds have since been tested for the virus, and face masks have become ubiquitous on subways and in shopping centres of the affected prefectures of Osaka and Hyogo in the central region of the main island of Honshu. The government has urged calm and reminded people that no one in Japan has so far died of the disease and that most infections are mild. Other Asian developments saw a German with suspected swine flu die in Thailand, China and South Korea confirming their fourth cases of the virus and Hong Kong under a new alert after a visitor from the mainland was thought to have brought the virus to a hotel in the Mong Kok area. Chan told member states at the opening of the WHO annual assembly on Monday they may be facing a calm before the storm but there was no reason to raise the alert level to its maximum six. Apart from 72 deaths in Mexico, swine flu has killed six people in the United States although the WHO lists five dead and one each in Canada and Costa Rica.