Homewood-Flossmoor Community High School was placed on lockdown Friday after a firearm and ammunition were discovered in a hallway following a student altercation, prompting a heavy police response.

Authorities were called to the campus at 999 Kedzie Avenue, where officers established a strong presence as they investigated the incident. School officials said the lockdown was implemented immediately out of an abundance of caution to ensure the safety of students and staff.

According to preliminary information, the weapon and bullets were found lying in a hallway after a fight involving students. It was not immediately clear how the firearm came to be on campus or whether it had been discharged. No injuries were reported.

Local law enforcement secured the school and began a search of the building while administrators worked to account for all students. Parents and guardians were notified as the situation unfolded.

Police have not released details regarding any arrests or potential charges, and it remains unclear whether the firearm was loaded at the time it was discovered. Investigators are continuing to determine how the weapon entered the school.

The lockdown remained in effect while authorities completed their investigation. School officials said additional information will be shared as it becomes available.