These are attacks that have occurred on school property or related primarily to school issues or events. A narrow definition of attack is used for this list to exclude attacks during warfare, robberies, gang violence, political or police attacks (as related to protests), accidents, single suicides, and murder-suicides by rejected spouses or suitors, as they are not the type of mass murder event that is the focus of concern. Incidents that involved only staff who work at the school have been classified as belonging at List of workplace killings. It also excludes events where no injuries take place, if an attack is foiled. Accounts without reliable sources are excluded.