Washington - US President Barack Obama is asking Congress for an added 1.5 billion dollars to fight the swine flu outbreak that has spread to five US states, his spokesman said Tuesday. The money will be used to "enhance the nation's capability to stop the spread," including stockpiling anti-viral drugs and develop and "ramp up production" of a vaccine, said Robert Gibbs.

Gibbs dismissed the suggestion that the money request indicated a new level of concern by the White House. "In our opinion, this is about prudent planning," he said.

Mexico City - The government of Mexico City banned eating in restaurants and ordered gyms, clubs, cabarets and billiards rooms to close, as measures to constrain the flu epidemic got tougher Tuesday. At least 152 people have died of flu in recent weeks in the North American country, but at the most only 20 deaths have been attributed to swine flu, raising further mystery about the other deaths.

But restaurants will still be allowed to sell meals to people who pick them up and eat them at home.

Washington - The number of human swine influenza cases in the United States increased to 64 Tuesday in five states, the US Centres for Disease Control and Prevention (CDC) said. The worst-affected was New York City, with 45 cases, while California reported 10 cases. There were 6 cases in Texas, 2 in Kansas and 1 in Ohio.

Those who have fallen ill in the US range in age from 7-54 years, with a median age of 16 years. There have been no deaths in the US.

Geneva - World Health Organization officials reiterated Tuesday that travel restrictions would not help stem the spread of the swine influenza virus, which was possibly spreading in the form of human-to-human transmission. "Border controls don't work, screenings don't work," said spokesman Gregory Hartl, speaking to reporters in Geneva. "Travel restrictions do not help."

The incubation period of the virus, which could be for up to six days, as well as the widespread nature, would make spot checks at airports, for example, ineffective.

Vienna - One Austrian woman was "likely" infected with swine flu and four others are suspected of having the same illness, Austrian Health Minister Alois Stoeger said Tuesday. All of the five had recently been to Mexico, the centre of the outbreak, the minister said at a press conference.

The most likely case is that of a 28-year-old woman in Vienna, who returned last week from a trip to Guatemala and Mexico, Vienna's chief health official Karin Spacek said.

Geneva/Brussels - Health experts appealed for calm Tuesday as the number of confirmed human infections from swine flu in Europe rose to four and governments sent out contradictory signals on how to deal with the spread of the virus. "Nobody should underestimate the situation, but there is no reason to panic either," Androulla Vassiliou, the European Union's health commissioner, said in Brussels.

As of Tuesday afternoon, four cases of swine flu had been confirmed in Europe - two in Britain and two in Spain.