School closures mostly prompted by the spread of H1N1 swine flu have begun increasing again, with 17,210 educational institutions reporting partial or full closures in the week up to Saturday, the health ministry said Wednesday.

The figure marked an upturn from the previous week, when partial or full closures fell to 15,149.

During the latest reporting week, Ibaraki Prefecture reported the most closures, with 1,040 institutions, followed by Kanagawa with 1,004, Saitama with 996, Osaka with 905 and Tokyo with 889. The institutions include nursery schools, kindergartens and elementary, junior high and high schools.

The number of hospitalized H1N1 patients logged between Nov. 4 and 10 was 1,309, a new high since late July, when the government began taking records.

The tentative figure in the following seven days was 724 — 455 men and 269 women, and about 90 percent of them were aged 19 and below. The Health, Labor and Welfare Ministry said 252 of them had chronic diseases that make them vulnerable to worsening symptoms.