All schools in the Los Angeles Unified School District were ordered to close and students were sent home after what was described as a “credible terror threat” by school district officials and police was received.
School district spokeswoman Ellen Morgan announced the closure on Tuesday but released no further details ahead of a press conference at district headquarters.
The district, the second largest in the United States, has 640,000 students in kindergarten through to 12th grade, more than 900 schools and a total of 187 public charter schools.
The district spans 1,150sq km (720sq m) including Los Angeles and all or part of more than 30 smaller cities.