Lafayette police locked down two schools Monday afternoon after an anonymous automated phone call reported a threat at Acalanes High School on Pleasant Hill Road, then responded to nearby Stanley Intermediate School minutes later.

Officers searched both campuses and found no danger.

The lockdowns lasted less than an hour.

The incident, which police said appears to be a case of "swatting," rattled families just one week into the new school year. Students at both schools had returned to campus Tuesday, Aug. 11.

Lafayette Police Department announced the Acalanes High School lockdown on X at approximately 12:01 p.m. Monday, Aug. 17.

A Nixle alert posted shortly after described the lockdown as precautionary while officers worked a potential threat called in by an anonymous automated call and asked residents to avoid the area.

Officers arrived at Stanley Intermediate School, located at 3455 School St., roughly 30 minutes later to investigate a similar concern.

By 12:48 p.m., police posted an all-clear for Acalanes. Stanley Intermediate followed five minutes later, at 12:53 p.m.

Lafayette police said officers completed a thorough search of Acalanes High School and determined the campus was clear, with no active threat to students, staff or the surrounding community. Preliminary information indicates the incident was likely a "swatting" call, the department said, describing it as a false report intended to prompt a large emergency response.

Students returned to their normal schedules after the all-clear.

Officers remained on the Acalanes campus as a precaution while the investigation continues, according to KRON 4. KTVU reported that police responded to Stanley Intermediate for what also appeared to be swatting.

The department has not disclosed the specific content of the threat or identified any suspects.