A record 2,253 public school teachers were reprimanded for corporal punishment nationwide in the 2012 academic year — up nearly sixfold from the previous year, the education ministry said Tuesday.

The sharp rise came as a large number of teachers were rebuked just before the school year's end in March 2012. The jump emerged after a stricter survey was implemented in the wake of an Osaka high school student's suicide that was linked to beatings he received from a teacher.

The ministry earlier identified 5,415 teachers as having imposed corporal punishment on students at public elementary, junior high and senior high schools in the year, up more than thirteenfold. More than half of the total were reprimanded in the 2013 school year and failed to be covered by the 2012 statistics.

Among the rebuked public school teachers, 176 were slapped with tough disciplinary sanctions, including three who were dismissed. The remainder faced lighter sanctions such as warnings.

In addition, 501 public school teachers were reprimanded for verbal abuse and other inappropriate actions, up from 98 the previous year.

The total number of public and private school teachers rebuked in the 2012 school year stood at 10,827. A record 206 were dismissed, including 119 who were charged with indecency and 46 in traffic accidents.

The ministry also said 4,960 teachers took leave due to mental disorders, including depression, in the 2012 academic year. This was the first time in five years that the level slipped below 5,000.