Authorities are investigating a threat made Friday via social media that was allegedly directed toward the Greenbrier School District.

Superintendent Scott Spainhour said Friday afternoon that the school and local authorities are working to track down the student responsible for making the threat.

Greenbrier Police Chief Gene Earnheart confirmed Friday evening that the Greenbrier Police Department was investigating the matter.

In a statement sent out to parents in the district Friday afternoon, Spainhour said school administrators were alerted by another student of the allegedly threatening post.

"A student reported having seen what appeared to be a threat on social media directed at the Greenbrier School District for the afternoon of April 18," Spainhour said in his alert to district parents, noting the post has since been removed. "Apparently, the post has now been removed from public view. The district immediate reported this to law enforcement, and an investigation is ongoing."

Spainhour said authorities will be onsite at each Greenbrier school and that all buildings will be locked on the day in question.

"There will be a strong law enforcement presence at each school on Wednesday and all buildings will remain locked," Superintendent Spainhour said Friday in his statement to parents. "We appreciate the prompt response of the Greenbrier Police Department, and the student for coming forward."