The US is on high alert since the San Bernardino massacre earlier this month
The US is on high alert since the San Bernardino massacre earlier this monthReuters

In an unprecedented move Tuesday, the Los Angeles school district has ordered all students to stay at home following a bomb threat.

Los Angeles Unified School District is the second largest school district in the US; the closure effects some 640,000 students in more than 1,000 schools.

At a press conference, LAUSD Superintendent Ramon Cortines justified the radical move in light of recent events.

"I think it is important that I take the precaution based on what has happened recently and what has happened in the past," he said. "Before the day is over, I want every school to be searched to make sure that it is safe for children and safe for staff to be there on Wednesday." 

"It was not to one school, two schools or three schools. It was many schools, not specifically identified. But there were many schools. That's the reason I took the action that I did ... It was to students at schools."

The threat was sent via email from an I.P. address in Germany to a LAUSD board member.

Also on Tuesday, a school in nearby San Bernardino - where a recent gun rampage by Muslim terrorists killed 14 people - was also closed due to similar threats. San Bernardino Valley College officials ordered students to stay home Tuesday following a bomb threat against the school.

The incidents comes as the US remains on a high state of alert, following the massacre in San Bernardino, just 60 miles east of Los Angeles.

Steven Zipperman, chief of the LA School Police, stated that the closure was merely a precaution, and urged the public not to panic.

"Earlier this morning we did receive an electronic threat that mentions the safety of our schools," he said. "We have chosen to close our schools today until we can be absolutely sure that our campuses are safe."

"I can tell you that we know of no other threats that we're aware of, unless other agencies have gotten specifics outside of LAUSD," he cautioned.

LA school board President Steve Zimmer called on residents to cooperate and help authorities bring the crisis to a speedy conclusion.

"We need to cooperation of the whole of Los Angeles today," he urged. "We need families and neighbors to work together with our schools and with our employees to make sure our schools are safe throughout today."

However, similar threats emailed to New York's school district were ignored, with officials there accusing their LA counterparts of overreacting.

New York Mayor Bill de Blasio sad the threats were simply not credible.

"There was nothing credible about the threat. It was so outlandish," he told reporters.

According to AP, New York Police Commissioner William Bratton noted that the email sender identified as a jihadist, but his message contained several mistakes which indicated the threat was not a serious one.