(KTXL) — Sonora High School in Tuolumne County was placed on lockdown for several hours Thursday, the Tuolumne County Sheriff’s office said.

The Sonora Police Department said multiple law enforcement agencies were investigating a report of shots heard near the school.

Around 5 p.m. police said the campus had been cleared and that students were released.

According to police, no one was injured and no suspicious activity was found.