CERES – Law enforcement officers swarmed a school in Central California late Monday morning due to reports of a possible gun threat, officials say.

The Ceres Unified School District said in a statement that they were alerted by Ceres police about a possible threat against Cesar Chavez Junior High School. That school, along with neighboring La Rosa Elementary, went on a precautionary lockdown. 

Officers swarmed the school and began searching. Deputies with the Stanislaus County Sheriff's Office helped in the investigation. 

No evidence of a threat was found, Ceres Unified officials said; all students and staff were safe. 

"Any threat against a school community is treated with the utmost seriousness," the district said in a statement. 

Many concerned parents congregated outside the school, waiting for updates about the situation.

It's unclear who was behind the initial report of a threat. 

Ceres is a Central Valley city just south of Modesto and about 80 miles south of Sacramento.