Japanese schools reported a record high number of bullying cases in fiscal 2017 as nationwide efforts led teachers to identify even minor cases in their early stages, the education ministry said Thursday.

Public and private elementary, junior and senior high schools as well as special schools reported a total of 414,378 cases of bullying in the year ended March, up 91,235 from a year earlier, according to a ministry survey.

The number of serious bullying cases resulting in students suffering severe physical and mental injuries rose to 474, up 78, while 10 of the 250 students who committed suicide during the reporting year had been bullied at school, the ministry said.

Elementary schools found the highest number of bullying cases at 317,121, up 79,865, followed by junior high schools at 80,424, up 9,115, and high schools at 14,789, up 1,915. The number of cases at special schools, which cater for students with learning difficulties, stood at 2,044, up 340, it said.

While 85.5 percent of the total bullying cases have been resolved, some were still being dealt with, according to the survey. About a quarter of the surveyed schools said they had not identified a single case of bullying in the year.

Asked to describe what form of bullying took place, teasing accounted for 62.3 percent of the total cases. Online slander accounted for 3.0 percent, with the number of cases rising to a record 12,632, up 1,853.

Of cases designated as serious incidents under the law on the prevention of bullying, students suffered serious injuries including broken bones in 191, while in 332 cases students stayed away from school for 30 days or longer in the year, with some of the cases overlapping.

The serious cases included that of a girl who died in July last year after falling from a Hiroshima junior high school building. The girl's parents claim she committed suicide and it was later confirmed she had been bullied.