Granite Bay High School has been cleared after being on lockdown due to a threatening note left on campus, according to the Placer County Sheriff's Office.

The school was put on lockdown at 2 p.m. on Tuesday.

The handwritten note stated a threat to "shoot up the school", which was found inside a student bathroom, according to a Roseville Joint Union High School District press release.

The sheriff's office was then notified and showed up at the school to investigate the incident. Deputies conducted a room-to-room search of the school.

The end of school was delayed due to the search, and there was a controlled release of students. There are no leads yet.

Earlier Tuesday morning, the entire school did practice a mock lock down event.

This is a developing story, stay with ABC10 for information as it comes in.