New Zealand Public Health Director Mark Jacobs announced on Tuesday night that results from some of the Rangitoto College students who tested positive to Influenza A on Sunday, have also tested positive for Swine Flu H1N1.

Results from three of the 11 samples were received earlier Tuesday evening from the World Health Organization regional laboratory in Melbourne and all tested positive for the same strain of Swine Flu. Testing was continuing on a fourth sample.

"On the basis of these results, we are assuming that all of the people in the group who had tested positive for Influenza A have Swine Flu. As a result we are continuing with the current treatment which has been based on this assumption," he told a press conference in Wellington.

"We were advised that the lab in Melbourne selected four of the best samples of the very delicate genetic material to analyze. They found three positive results and one is still to be confirmed, " he added.

The school group returned to New Zealand on Saturday from a trip to Mexico, the presumed source of the worldwide swine flu outbreak.

Staff from Auckland Regional Public Health were contacting those affected and informing them of the results. All are understood to be recovering at home.

Those affected will continue to receive the anti-viral drug Tamiflu and will remain in home isolation.

All 356 passengers on the flight into Auckland on Saturday with the Rangitoto College group had been urged to stay at home in quarantine. Officials said they have traced all but 18 passengers on the flight and they are being given Tamiflu.

The New Zealand government has asked airlines to make sure a statement providing advice and information on swine flu is read out on all incoming flights to New Zealand.

Health Minister Tony Ryall Ryall said the measure was in response to the increasing international spread of the potentially fatal virus. In addition, the Health Ministry has requested that a travel health notice be given to all incoming passengers on arrival.

The New Zealand government has warned against non-urgent travel to Mexico.

The government said a further 43 people with flu-like symptoms were being tested for influenza A, which may point to swine flu.

Officials said people who have traveled to Mexico or North America recently and has flu-like symptoms should phone their family doctor, but others with such symptoms have normal winter illnesses.

The Ministry of Health said people who have traveled to North and South America in the past fortnight should contact the health authorities.

(Xinhua News Agency April 28, 2009)