A number of less serious incidents have also made news.
During her service life, she was involved in a number of incidents.
But the total number of reported incidents is still small.
We've had a number of incidents in the last few weeks.
However, the number of such incidents rose to four in 2004.
In 1960, the number of incidents fell to just 26.
The schools are much more dangerous than 20 years ago, although the number of serious incidents last year, 3,843, was down from 5,233 in 1984.
The number of incidents during games grew in the 1980s.
This year, as the number of incidents rose further, two students were killed in the schools.
"In the last few days, a number of incidents have taken place," he said.