Public schools were closed across Los Angeles on Tuesday following a “credible threat” of an attack, officials said.
Students were sent home as officials planned a search of schools in the Los Angeles Unified School District, the county sheriff’s department said.
The Los Angeles Police Department said the threat was received as an “electronic” message. The FBI and police are investigating.
Police Chief Charlie Beck said the message, which was traced to an IP address in Germany, threatened an attack with assault rifles and machine pistols.
NBC News reported that at least one member of the school board received an emailed bomb threat, citing multiple law enforcement sources.
School district Superintendent Ramon Cortines said the closure was ordered out of an “abundance of caution.”
He added: “I am not taking a chance of bringing children into a place, into any part of a building, until I know that it is safe. I, as superintendent, am not going to take the chance with the life of a student.”
He said the threat was made to numerous schools but declined to give further details.
The district is the second largest in the US and encompasses more than 900 schools and 640,000 students.
President Barack Obama has been briefed on the decision and his national security team is following developments, White House spokesman Josh Earnest said.
Meanwhile, New York City officials said a “specific but non-credible threat” was made against unspecified schools Tuesday morning. It was not immediately clear whether the threats were related.
The closures came less than two weeks after the killing of 14 people in San Bernardino by a couple thought to have been inspired by DAESH.