Japan, Australia confirm first cases of A (H1N1) flu (Update)

Japanese authorities scrambled Saturday to track travelers who arrived on the same flight as three people diagnosed with the country's first confirmed cases of swine flu.

Australia also joined the ranks of affected countries with its first confirmed case.

Authorities in Tokyo quarantined a high school teacher and two of his teenage students who returned Friday from a school trip to Canada on a flight from the U.S. after they tested positive at the airport.

But news reports said as many as 11 people on the Northwest Airlines flight from Detroit that landed in Tokyo on Friday avoided those screenings. Another 13 continued on to other destinations, including Thailand and Taiwan.