Japan's All Nippon Airways (ANA) said on Monday that all cabin crew will wear face masks on all incoming flights from the United States as a prevention measure swine flu.
Japan's second largest airline decided on the measure Saturday, when Japan confirmed its first A(H1N1) cases -- a school teacher and three students who arrived from North America with another airline -- the company said.
"We believe this measure provides a sense of security as cabin attendants come into contact with many people and serve meals," a spokeswoman said.
ANA operates daily flights from five US mainland cities. Its twice-weekly flights from Vancouver and Toronto are operated by Air Canada under a code-sharing agreement and are not subject to the mask requirement.
Japan Airlines (JAL) has required cabin attendants to wear masks on twice-a-week flights from Mexico since early May.
It has not taken the same measure on US flights but the company is closely watching the global spread of the flu, JAL spokesman Taro Namba said.