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NEW JERSEY – Robotic voices threatened to blow up schools or kill police officers in northern New Jersey and across the northeastern United States on Tuesday. Over two-dozen schools in 9 towns in Bergen County were threatened. Clifton and Sayreville, N.J. also received calls. Each district handled the threats differently, but all received thorough searches by bomb squads.

Investigators were able to trace the calls to Bakersfield, California.

“Apparently this is coming through recycled, computer-generated numbers,” said Bergen County Sheriff Michael Saudino.

Outside Garfield High School, police were out in force and bomb-sniffing K-9s were deployed. Students were kept inside on lockdown.

One father of two said he dropped his daughters off, only to watch cops swarm schools a short time later.

“I was a little worried. My own wife kept calling me back and forth, and then when I saw the cop cars leave, I started breathing again,” said Goran Lazoroski.

In Fair Lawn, district administrators made the call to evacuate students.

While in Teaneck, students backpacks were confiscated and searched at the town’s community center. Once deemed safe, they were loaded onto trucks and driven back to schools.

In Hackensack, some parents chose to pick up their kids early.

“I was scared for all the kids,” said Hackensack parent Chris Manning.

Schools across the northeast faced similar threats today. Reports out of Boston say that 15 schools received threatening, automated phone calls. Many of the same schools were also reportedly threatened on Friday.

Schools outside Philadelphia and Baltimore also receiving threatening calls today, reports say. The trend even reached the United Kingdom, where some schools reportedly closed.

So called ‘swatting’ – calling in phony threats to prompt a big police response – is nothing new. There was a spate of them in the New York region last year. Police say the problem is that many keep getting away with it. Some companies, they say, can make these robotic calls very difficult to trace.

“It’s my hope that federal legislators will look at this thing,” said Sheriff Saudino, “[it’s time to stop] the protection of some of these companies, where they hide the identity of people that are doing these types of calls.”

Nonetheless, investigators say they are committed to tracing the digital fingerprints in this case, to find out who was behind it.