Three high school students and a teacher from Osaka who were the first people in Japan confirmed to have the new flu have become the target of malicious phone calls and e-mails, local board of education and municipal officials said Friday.

The four arrived at Narita airport from Canada via the United States on May 8 aboard a Northwest Airlines flight.

On Friday, all but one of a group of 48 passengers and crew, including 32 high school students who were on the same flight and have been quarantined at a hotel in Narita, were discharged, the health ministry said.