ELIZABETHTOWN (AP) — Officials in Bladen County say two 15-year-olds have been placed under house arrest and two other teens have been arrested after threats of violence were made against two different schools.

A news release from the Bladen County Sheriff’s Office said several West Bladen High School students received Instagram messages on Jan. 18 telling them to stay away from school because there would be violence the next morning. The sheriff’s office itself received word of a threat against Bladenboro Middle School.

On Tuesday, students at West Bladen showed a teacher a Snap Chat message that threatened violence. Investigators said two teens, aged 17 and 16, were charged as adults with making a false report concerning mass violence on educational properties. A 14-year-old was to be served with a juvenile petition.