File Photo – Lake County Sheriff Canine Boomer. | Provided Photo.

Police are working to identify the suspect who called in a bomb threat to the North Chicago High School, which caused the school to be evacuated Friday and an explosives detection dog to be called to the scene.

North Chicago District 187 Superintendent John Price said that an unknown person called in a bomb threat to the main office of the North Chicago Community High School around 8:30 a.m. Friday.

The school was placed in lockdown and the North Chicago Police Department was contacted, Price said.

Police had the building evacuated and called a canine unit to complete a search of the property.

Buses were called for student transportation and parents were notified of an early dismissal for students.

A gradual release of students occurred starting at 9:45 a.m. with the school completely evacuated shortly after 10 a.m., Price said.

Lake County Sheriff Canine Boomer, who is an explosives detection dog, responded to the scene with his handler Deputy Brian Kilpatrick, the sheriff’s office said.

Boomer conducted a sweep of the building and verified there were no explosives. All students and staff are safe.

The North Chicago Police Department is still investigating and “will soon locate the prank caller,” Price said.

The school district said it is their intent to discipline and file charges against the person responsible for making the threat.

“We will keep you informed as more information becomes available. You are encouraged to contact the North Chicago Police Department if you have any information,” the school district said.

“The safety of our students and staff is our top priority. Rest assured that every effort was made to keep everyone safe and will be made to locate the person responsible for this crime,” Price said.