Authorities investigating online threats made against Southern High School in Maryland

Anne Arundel County Public Schools said there will be additional security at Southern High School on Thursday after they were made aware of threats made on social media against the school.

The school system sent out a robocall to parents Wednesday night informing them of the threats, which do not appear to be credible at this time. They said they are working with police on the matter and the extra police presence is being added as a precaution.

"Please be assured that our school system and county police are taking this matter very seriously and working aggressively to identify those responsible for the posts," the robocall said in part.

Southern High School is scheduled to open on time Thursday morning.