With new cases reported in Osaka and Hyogo prefectures, confirmed cases of A/H1N1 flu amounted to 281 in Japan on Thursday.

During a budget committee session at the upper house, Health, Labor and Welfare Minister Yoichi Masuzoe said that the A/H1N1 influenza has been "substantially widespread" in Japan.

The government will follow the ever-changing situation and try to strike a balance between the need for anti-epidemic measures and avoiding strains on people's lives, he said.

On Wednesday, two school girls were confirmed to be infected with the new flu in Tokyo, becoming the first cases outside the Kansai region.

The Tokyo metropolitan government has instructed three high schools to keep nine students and teachers, who were in New York with the two infected girls, from attending school.

Meanwhile, the health authorities were attempting to track 17 people who had close contact with the girls on the same flight back from New York.