GARFIELD HEIGHTS, Ohio (WJW) – An alert bus driver prompted the call that led to a lockdown at Garfield Heights Middle School and sent children home early on Monday.

According to the Garfield Heights police chief, after students arrived at school and got off the bus Monday morning, the bus driver found a bullet underneath one of the seats. The driver then watched as a student who was sitting in the seat went to a trash can outside of the school and appeared to put something in it.

When security checked the trash can they found a handgun magazine that was loaded with four rounds.

Police say the school was immediately placed in lockdown and the student(s) involved were identified and detained.

A gun was never seen or found, according to police.

It’s not clear if those involved will face charges. Police say information will be forwarded to the Juvenile Detective Bureau for review.

According to a post on the district’s Facebook page, all middle school students were sent home early.

School officials said the early dismissal allowed the Garfield Heights Police Department to “thoroughly complete their safety and security assessment of the building.”

The district said middle school students who walk to school would be transported home by bus.

The district wrote: “Students riding the bus can expect to arrive home within the next several hours. Please be advised that students who have extenuating circumstances will be dealt with on a case-by-case basis. Thank you for your patience, and for supporting the Garfield Heights City Schools, to ensure the safety and security of everyone.”

Parents can also pick up their children if they choose.