UPDATE: Officials with Madison County Public Schools report the investigation into a threat against the high school and Wetsel Middle School has concluded.

The Madison County Sheriff's Office brought in a K-9 unit to conduct a search of the schools, and the all-clear has now been given.

Officials believe the robocall that was the source of the threat is part of a nationwide hoax and there is no threat at this time.

MADISON COUNTY, Va. (CBS19 NEWS) -- Some Madison County students have been evacuated while an investigation looks into a threat.

Parents with students at Madison County High School and Wetsel Middle School should have received a phone call regarding the situation.

The school division and local law enforcement officials are investigating a threat that was communicated to the school around 11 a.m. Tuesday.

All evacuated students and staff are safe and being supervised.

Parents who would like to pick up their child can do so at the blue tower in the back parking lot behind MCHS for high school students or at the track behind Wetsel Middle School for students there.

Both buildings are being searched at this time.