VIRGINIA BEACH, Va. — Authorities say they have investigated 21 cases involving threats to public schools in Virginia Beach since the school massacre in Florida.

The Virginian-Pilot reports that 10 juveniles have been charged in recent days with various misdemeanors and felonies, including communication of a threat to a school.

All of the charged youngsters are middle- and high-school students.

The newspaper quotes Virginia Beach Police Chief James Cervera as saying “threats against a school are not a misunderstanding — it’s a crime.”

There have been numerous threats to schools across the nation since the Feb. 14 shooting rampage at the Marjory Stoneman Douglas High School in Parkland, Florida.

The attack left 17 students and adults dead.

Information from: The Virginian-Pilot,