UNITED NATIONS - Amid the rapid spread of swine flu in some countries, the UN health agency Monday night raised its pandemic threat level one notch, saying the dangerous new virus was clearly causing sustained community-wide outbreaks. Following the advice and guidance of an emergency committee, Margaret Chan, Director-General of the Geneva-based World Health Organisation (WHO) decided to raise the alert level from the current Phase 3 to Phase 4 on a scale of 6, a WHO official told the news media on a teleconference. A raise to Phase 4 means the swine flu virus can cause sustained human-to-human transmission and community-level outbreaks, indicating a significant increase in the pandemic risk. But raising the alert level does not necessarily mean a pandemic is considered inevitable, Keiji Fukuda, the WHOs temporary assistant director-general for Health Security and the Environment told reporters via a web Press conference. The new virus strain, a subtype of A/H1N1, has not been detected in swine or humans before. With little or no resistance from the human immune system, the strain has the ability to aggressively attack the body and become deadly. Ms Chan, the WHO chief, has said containment is not feasible at this time and instead efforts should be focused on mitigation. Either closing borders or restricting trade would have very little effect of stopping the movement of the influenza strain but it would cause a great deal of disruption for countries, said Fukuda. However, Fukuda urged people experiencing flu-like symptoms to delay travel and seek immediate medical attention. In its third and last recommendation, the WHO chief considered that production of seasonal influenza vaccine should continue at this time, subject to re-evaluation as the situation evolves. As there are a number of parties involved, the WHO will facilitate the process needed to develop a vaccine effective against the A/H1N1 virus. In Mexico, there have been 1,614 suspected cases of swine flu, including as many as 149 deaths. UN Secretary-general Ban Ki-moon on Monday noted that the deaths in Mexico were of particular concern because those who died were young and healthy adults. Indiana became the sixth US state to report a case of swine flu Tuesday with officials saying the infected person, who had not visited the outbreak epicenter of Mexico, was recovering. The single case in northern Indiana took the total number of confirmed US infections to 65. Suspected or confirmed cases of swine flu were also reported in Scotland, Canada, New Zealand, Israel, France, Spain, Austria, South Korea and Brazil. At UN Headquarters in New York, Secretary-General Ban Ki-moon made an unscheduled appearance at the regular noon briefing to highlight UNs role in dealing with the health emergency. The UN system is responding, quickly and effectively, with the DG of the WHO, Dr Margaret Chan, taking the lead, he told reporters. Announcing that the World Bank and other UN development and humanitarian agencies will provide funding to countries needing additional resources to combat an epidemic, Ban said that the poorer nations must not be hit disproportionately hard by a potential health crisis. Flu death toll has risen to 150. So far, our response has been an example of multilateral cooperation at its best. I am confident that it will continue to be so, he added. Meanwhile, a team of experts from the UN Food and Agriculture Organisation (FAO) is helping to determine if the new virus strain has a direct connection to pigs. FAO will also dispatch a team of animal health experts to Mexico this week to help the Government assess the origin and transmission of the infection in the pig production sector. Flu death toll has risen to 150.