A bullet was discovered by a student inside the hallway of John Read Middle School Thursday, school officials say.
The discovery was made at the middle school around 9 a.m. The .22 caliber bullet was turned over to an administrator.
Officials say the Redding Police Department's K-9 unit and State Police responded to conduct a sweep of the building, and no weapons or additional bullets were discovered.
During the search, school officials say students were kept inside their classrooms and the lunchroom.
Classes are scheduled to resume regularly, according to Superintendent of Schools Tom McMorran.
"I am highly confident that this incident, and the police response to it, assured the ongoing safety of our children and staff," McMorran wrote in an email to parents.
Redding police say the incident remains under investigation. McMorran says counselors will be at the school if students want to talk about the incident. He also encouraged students to talk to their parents if needed.