Students from a second Hastings secondary school have been caught up in the swine flu outbreak.
Twenty-six students and four teachers from Lindisfarne College are in isolation after returning from a music tour through the United States that included time in California.
Hawke's Bay District Health Board says the first of the potentially affected students from the college were identified on Thursday.
By Friday afternoon, 11 students from Hastings Girls, who were on the same tour, voluntarily isolated themselves.
Lindisfarne College rector Grant Lander says the group was put in isolation on the advice of the local health board, and tests were taken from three of the group. Only two of the students are in isolation at the school, the others having been sent home.
Mr Lander says test results taken from some of the students may not be back until next week.
The district health board says all those affected appeared well.
Thousands of people worldwide are being tested for the swine flu virus, or H1N1, which is thought to be responsible for up to 176 deaths in Mexico.
Meanwhile, the Government is ordering more supplies of anti-viral drug Tamiflu.
Health Minister Tony Ryall says there are 1.25 million courses of Tamiflu available in case of a pandemic.
A new order has been placed to increase that stock by 10% to 1.37 million. Stocks of another anti-viral drug, Relenza, have also been ordered.
Extra supplies of the seasonal flu vaccine have also been ordered because of a higher than expected demand.
The Ministry of Health says 8,000 courses of Tamiflu are on pharmacy shelves, but if they are sold out there may be no more in the immediate future because manufacturer Roche has limited stocks.
Mr Ryall says medical staff from around the country are in Auckland to help with efforts to combat the swine flu outbreak. He says 180 staff have been a part of the operation.
Mr Ryall says Auckland District Health Board and regional public health workers have been supported by others from Waikato, Hawke's Bay, Wellington and Bay of Plenty.
He says up to 15 nurses have come from other district health boards, while another 10 to 15 are helping with border control.
Three public health doctors from Wellington, six public health registrars and a public health specialist are also part of the effort.
Confirmed cases at four
Mr Ryall says the number of confirmed cases of swine flu in New Zealand has risen to four, and he expects the number to keep rising.
Those four people all travelled into New Zealand from Mexico on flight NZ1, and so did another 11 people who probably have the flu, he says.
The number of probable cases has gone down by two, including a passenger from California who Mr Ryall says has tested negative.
Nationally, there are 401 people in isolation, and 136 of those are displaying flu symptons.
Mr Ryall says the Government will provide hospitals with extra support if it is needed over the winter flu season.
He says health authorities have done a good job of isolating and treating people with symptons.
Tamiflu has been offered for sale on website TradeMe on Friday,
though the seller's entries have been removed by the company's staff.
TradeMe business manager Mike O'Donnell says that by early afternoon, six people had tried to sell the drug.
Mr O'Donnell says staff let the sellers know that their auctions broke the site's rules.
Tamiflu can be sold only by pharmacists who meet patients in person.
Medsafe group manager Stewart Jessamine says that rule is in place in part because of the risk of the drug being sold over the internet.
Minister in voluntary isolation
Cabinet Minister Nick Smith has been in self-imposed isolation at his Wellington home after becoming sick with influenza A.
Tests have since shown that he does not have swine flu.
A spokesperson for the Nelson MP says Dr Smith felt unwell and began suffering high temperatures on Tuesday. He saw his doctor on Wednesday who advised him that he had influenza A, but was not likely to have swine flu. He is being treated with Tamiflu.
The spokesperson says Dr Smith chose to remain home as a precaution and has not been to North America or Mexico recently.
Easing of Tamiflu restrictions urged
The Pharmacy Guild has asked health officials to consider changing the rules for sales of Tamiflu, which can be bought without a prescription from pharmacies from Friday.
Tamiflu is sold only to people displaying flu symptoms, and will not be given to those who simply want to have some on hand as a precaution.
The guild says family members of sick people should be able to pick up the drug on their behalf to save potentially contagious people spreading illness.
However the Ministry of Health says there is no need to change the controls.
The Medical Association says GPs are concerned they are being touted as the first port of call for people with flu symptoms, but are not being offered the right support or equipment, such as access to masks.
Overseas student advice
Overseas students planning to study in New Zealand are being told there is no need to put off their travel plans because of swine flu.
Education New Zealand has issued offshore agents with a statement saying a widespread outbreak is highly unlikely in New Zealand and the Government is taking the issue seriously.
Chief executive Robert Stevens says the international student market is worth $2.3 billion a year to the economy and needs to be protected.
Discrimination against Mexican citizens feared
The Mexican embassy in Wellington fears citizens from its country could be a target of discrimination following the swine flu outbreak.
The embassy has issued a statement saying the New Zealand public is being misinformed about the outbreak, with overly dramatic media headlines.
Charge d'affaires Luis Enrique Franco says Mexico is taking precautions to prevent the virus spreading, including closing schools and businesses.
He says Israel is calling the illness "Mexican flu" and is appealing for the nation and its citizens not to be singled out.