Schools across the U.S. have been rocked by a spate of false threats of violence in recent weeks, forcing them to evacuate or temporarily close. Why it matters: Threats of bombs, shooters and other dangers disrupt learning and stir community-wide anxiety about school safety.

Following a series of school shooting threats directed at several Fresno-area schools earlier this month, the city’s police department announced on Tuesday that even more arrests have been made. The Fresno Police Department has revealed several arrests this school year to highlight that threats will be taken seriously.

Threats against schools are increasing following a shooting at a high school in Barrow County, Ga. It is a recurring phenomenon that follows many tragic events.