A 10-year-old student has been charged with felony terrorist threat for allegedly threatening to commit a school shooting at a Kerrville, Texas, middle school, police said Monday.

The number of threats of violence against area schools has risen to the dozens as school safety concerns spike nationwide, local and federal law enforcement officials said Friday.

The charges are part of a sprawling investigation into more than 60 threats targeting schools in 23 counties since a mass shooting on Sept. 4 in Georgia in which four people were killed at a high school.