All public schools in the vast Los Angeles area have been ordered closed due to a threat, police have said.
According to BBC News, officials would not specify the nature of the threat, which led to students being sent home, but police are searching all the schools, which will remain closed until the threat is over.
“Earlier this morning we did receive an electronic threat that mentions the safety of our schools,” said Steven Zipperman, chief of the Los Angeles school police department told reporters at a press conference.
The district is the second largest in the US, with 640,000 students attending more than 900 schools.
The threat comes amid a heightened alert after 14 people were killed by a radicalized Muslim couple in San Bernardino, 60 miles east of Los Angeles.