It is not yet known if any of the detained passengers actually have H1N1 influenza A, or swine flu.
Japanese health officials allowed the crew and passengers to go after testing one passenger with flu-like symptoms, American spokesman Tim Smith said.
The passenger, a Japanese woman returning from Las Vegas, tested negative for the H1N1 virus.
When the flight arrived, government health inspectors quarantined one passenger and took the passenger to a Tokyo hospital for tests.
Other passengers who were sitting nearby on the flight were taken to a hotel, where they were held under the observation of health officials. Two flight attendants who were working in the same section of the Boeing 777 were also detained.
Japan uses body scanners to check the temperatures of incoming passengers, and the country has stepped up screening since the start of the global swine flu outbreak.