ST. CLAIR COUNTY, Ill. – East St. Louis Senior High School will be shut down Friday after receiving a bomb threat against the school.

The closure served as a precautionary measure as the school worked with law enforcement to investigate the validity of the threat and to complete a comprehensive search of the campus.

According to the East St. Louis School District-189, student arrivals were temporarily rerouted to a safe, alternative location. All bus riders are set to return home around 9 a.m.

All other schools in the East St. Louis School District-189 will be in session Friday, officials say. The investigation is ongoing and the school district is actively gathering information.