China said on Saturday it was to put all passengers on a flight from Mexico to Shanghai under quarantine after a man on the plane tested positive for swine flu, in the first confirmed case in Asia.
The 25-year-old arrived in Hong Kong on Thursday from Shanghai, where he had transferred from flight AM098 from Mexico, and news of his positive test immediately prompted China to suspend flights from the flu-hit country.
China "has asked health authorities in Beijing, Shanghai and Guangdong to immediately put passengers on flight AM098... under quarantine and a seven-day medical observation," the health ministry said on its website.
The ministry said it had also asked authorities to track passengers who had already gone onto other provinces, as China entered its second day of a Labour Day break that is seeing millions travel around the country.
The Mexican man, who is in a stable condition, was admitted to hospital in Hong Kong on Thursday night suffering from a fever and tested positive on Friday for the A(H1N1) flu virus.
The hotel where he had been staying has been isolated, and more than 300 guests and staff there were placed under quarantine for seven days in a bid to contain the virus.
China's health ministry also said it had given Hong Kong authorities information about passengers on the China Eastern Airlines flight from Shanghai that carried the Mexican man.
China was "tracking down all crew members of that flight to put them under quarantine and medical observation."
It also called for all passengers on both flights to get in touch with health authorities "to ensure that all passengers can get timely medical tests."
The Mexican government has meanwhile raised its confirmed toll to 16 dead and 381 people infected and the country is in a five-day shutdown until Tuesday to halt the virus's spread.
South Korea also confirmed on Saturday its first case of swine flu.