MOBILE COUNTY, Ala. (WKRG) — Just four days after students in the Mobile County Public School System return to the classroom, two high schools and an elementary school have received threats of shootings.

A post was made on the popular social media app Snapchat that said Murphy High School and Baker High School were going to be “shot up.” The post also said the person would be going to an elementary school in the area.

Officials with the Mobile Police Department said they have three juveniles detained for their involvement in the threats. Officers said once the investigation is complete they will determine what the charges against the juveniles will be.

“Protocols have been followed to increase safety at schools while the matter is investigated,” said Mobile Police officials. WKRG News 5 reached out to officials at MCPSS but have not heard back.