A container for transporting swine flu virus samples exploded on a Swiss train, authorities said Tuesday, but stressed that there was no danger to the public. The container, which was filled with dry ice and carried samples of the H1N1 swine flu virus, was destined for Switzerland's national influenza centre in Geneva, exploded Monday night on board of a train.

A laboratory employee had picked up the samples in Zurich to transport them by train to Geneva, but the package exploded near Fribourg and Lausanne, after melting dry ice, which had been wrongly places, caused a build-up of pressure.

Hong Kong  - Hong Kong is at a "higher risk" of an outbreak of swine flu because the city of 7 million is so densely populated, its leader Donald Tsang said Tuesday.

Beijing-appointed Tsang made the remark after government officials held a teleconference with counterparts in Macau and the neighbouring southern Chinese province of Guangdong.

The former British colony has been on alert for signs of the virus and Monday announced that three people tested for swine flu had been given the all-clear.

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.