The health ministry said Friday 92 passengers and crew members aboard a flight from Chicago to Narita airport near Tokyo were allowed to enter Japan without being asked to self-isolate for 14 days and refrain from using public transport.
Those departing from the United States after midnight Wednesday in Japan are subject to the self-quarantine measures to contain the spread of the new coronavirus.
The ministry said the airport's quarantine station miscalculated the time difference and omitted All Nippon Airways Co.'s Flight NH11 from those covered by the new step despite it having left Chicago at 1 a.m. Thursday Japan time.
The ministry said it has been asking passengers and crew to self-isolate and is trying to confirm their health condition after obtaining the flight's passenger list.
"This incident is really regrettable and shouldn't have happened," health minister Katsunobu Kato said at a press conference.
Travelers are required to isolate themselves at their homes or hotels during the two weeks. The measure is effective through the end of April.