Following a call reporting a shooting on campus, Hoover High School in Fresno was placed under quarantine.
The caller claimed he was hiding in the toilet and unable to move due to blood on the floor.
Authorities said the call may have come from overseas and that the caller had an older Middle Eastern accent.
In response, police conducted a thorough search of the campus, including every bathroom and classroom, and determined the call was a false alarm.
Emergency services, including the Fresno Fire Department and EMS, were at the scene as a precaution.
The lockdown has since been lifted.
FOX3 was able to speak to one of the students who is present at the school at the moment, he said everything is clear and the police have been going through all the classrooms to make sure everyone is okay, but no information has yet been communicated to us.