Authorities Tuesday were investigating undisclosed social media posts involving Taft High School in Woodland Hills to determine if there was a credible threat, police said.
Officers were sent to the campus in the 5400 block of Winnetka Avenue at about 9 a.m., according to the Los Angeles Police Department.
The school was not placed on lockdown, police said. A line of parents formed outside the campus, according to report from the scene.
The investigation was being conducted by the LAPD and school police officers.