The Joliet Police Department received a call on Tuesday from an “unknown” person communicating a threat “related to the outside vicinity” of Joliet Central High School.

The department received the call at 11:42 a.m. and responded “immediately” and in “close coordination” with school administrators to implement safety procedures that included a temporary lockdown, according to Joliet police officials.

Joliet Central High School, Pathways, and the Transition Center were placed on lockdown as officers “conducted a systematic search of the surrounding area,” police said.

“At this time, no evidence of a credible threat has been located and the incident has been determined to be fully unsubstantiated,” police said.

The lockdown lasted less than a hour.

“We appreciate the patience of our students, parents, and staff. Safety is our top priority,” Joliet Township High Shcool District 204 officials said on its Facebook page.

Throughout the incident, the police department remained in “constant communication with school officials focused on the safety and well-being of students, staff and the surrounding community,” police said.

“Out of an abundance of caution, an additional police presence will remain at the school through dismissal,” police said.

Anyone with information related to this incident is encouraged to contact the police department’s investigations division at 815-724-3020.

If they wish to stay anonymous, they can contact Will County Crime Stoppers at 800-323-6734 or submit a tip online at crimestoppersofwillcounty.