KOBE (Kyodo) Some high schools in Hyogo Prefecture whose students have contracted the H1N1 flu have at least one thing in common — their volleyball teams played in some of the same tournaments and even had matches against each other earlier this month.

With the infection routes yet to be determined, school officials involved in the matches are complaining that the volleyball teams are being singled out as a scapegoat, saying they are concerned that many players could suffer from a sense of guilt.

As of Monday, members of the volleyball teams from five high schools in the prefecture were confirmed to have been infected with swine flu. The schools are Kobe High School, Hyogo High School, Takasago High School, Yoka High School and Wadayama High School, Hyogo officials said.

Japan's first confirmed case of domestic infection involved students from Kobe High School's volleyball team.

The Kobe and Hyogo teams happened to be in the same gymnasium May 2 for a tournament and then faced off against each other May 8.

The Takasago and Kobe teams held a match May 10, while Yoka and Wadayama played each other May 9 and 10 in a tournament.

According to people who saw the match between Kobe and Hyogo on May 8, some students were cheering for their teams by blowing up balloons and releasing them into the air like Hanshin Tiger fans.