Some 51.7 percent of kindergartens and elementary, junior high and high schools nationwide have conducted drills against possible intruders, according to an education ministry survey released Thursday.

The survey by the Education, Culture, Sports, Science and Technology Ministry was reported at a meeting of school security officials that the ministry hosted in Tokyo following a recent series of school intrusions in which children were killed or injured.

The survey covering 54,249 public and private schools nationwide as of Nov. 1 said 53.1 percent of kindergartens conducted anticrime drills or seminars between April and November, while 53.4 percent of elementary schools had conducted such drills or seminars.

Only 50.7 percent of junior high schools and 44.8 percent of high schools conducted such drills or seminars during the period.

Of the 43,794 public schools surveyed, 52.9 percent said they had held such drills or seminars for students. The figure ranged between 71.7 percent and 76.4 percent in Nara, Osaka and Ibaraki prefectures, and was around 30 percent in Shimane, Tottori and Miyazaki prefectures.

As to why some schools failed to conduct such drills, they said they feared the drills would frighten students instead of preparing them to be on guard against intruders.

Some said they could find no appropriate organization to guide them in the drills, while others said they plan to conduct the drills in the next fiscal year or later.

According to the survey, 62.6 percent of the schools conducted drills or training seminars for teachers on how to prevent such crimes or to ensure safety.