A student at a junior high school in the Inland Empire sent in an anonymous threat, sending the school into a voluntary lockdown, officials said.
Before the lockdown was lifted at 10:55 a.m., police officers were going from room to room at Magnolia Junior High School in Chino checking to determine if the threat was real, a school district official said.
The threat was made about 7:45 a.m., possibly on the app KIK. It is unknown what kind of threat it is, officials said.
Officials are still investigating the threat.