Seoul  - South Korean authorities were investigating a possible case of a swine-flu infection Tuesday.

An influenza infection was detected in a 51-year-old South Korean woman who returned from a trip to Mexico on the weekend, the Korean Centres for Disease Control and Prevention said.

The centre was testing whether the woman contracted the mutated H1N1 virus, the strain identified in the swine-flu outbreak in Mexico, which may have cost up to 149 lives so far. Test results are expected in one or two days, the centre said.

New Delhi  - India has advised its citizens against visiting nations hit by a swine flu outbreak and is screening passengers coming from these countries, news reports said Tuesday.

The federal Health Ministry held a meeting Monday to discuss measures to prevent the flu, which spreads among humans through contact with infected pigs, from reaching India.

After the meeting a travel advisory was issued against visiting Mexico, the United States, Britain, France, Canada and New Zealand, the PTI news agency reported.

Tokyo  - The Japanese government on Tuesday urged its citizens to postpone trips to Mexico and those who live there to return at an early date.

Prime Minister Taro Aso has set up a task force Tuesday morning and raised the alert level after the World Health Organization (WHO) upgraded the pandemic alert level to phase 4, following a swine flu outbreak in Mexico which may have caused as many as 149 deaths so far.

Phase 4 means that there is sustained human-to-human transmission of the virus in at least one country, according to the WHO.

Mexico City  - Mexican Health Minister Jose Angel Cordova Villalobos said late Monday that number of people dying from an infection with a mutated swine flu virus rose slower than expected.

Six people died on Saturday, five on Sunday and three on Monday, Cordova said. The number of new infections was also slowing down, from 145 registered new cases to 110 in the past 24 hours.

Wellington  - Nearly 70 New Zealanders may have contracted swine flu following recent visits to Mexico or the United States, health officials announced Tuesday.

Another 56 people who had developed flu-like symptoms were being tested to see if they had the influenza A strain, which has been linked with the outbreak of swine flu, H1N1, that the World Health Organization said was evolving rapidly.

Mexico City  - Mexico on Monday closed schools and universities until May 6 and limited commercial activity in the capital to stop the spread of swine flu.

Mexico is believed to be the epicentre of the swine flu outbreak. An estimated 149 people have died from influenza, but only 26 deaths have so far been linked to the swine flu virus.

The US Centres for Disease Control and Prevention and the State Department issued an advisory late Monday urging against non- essential travel to Mexico, in effect through July.