New Zealand on Tuesday became the first country in the Asia-Pacific region to confirm cases of swine flu as Chinese authorities closed down a school in Shaanxi province and Japan tightened up visa requirements for Mexicans.

New Zealand said three of 11 people in a school group that visited Mexico had tested positive and it expected the others would also turn out to be positive when tests were completed. Health Minister Tony Ryall said all those affected appeared to have only mild symptoms and had been responding to treatment.