CRESSKILL, N.J. (CBSNewYork) — Security scares stirred panic Monday at several schools in New Jersey and New York.

In Bergen County, Cresskill Middle and High schools were locked down for about four hours and SWAT teams were called in after police said the schools received a threatening call at 9:49 a.m. that a gun was inside a building there, CBS2’s Meg Baker reported.

Police said all students were safe, and the situation was later deemed to be an incident of “swatting,” in which a fake threat is reported to provoke a massive police response.

Cresskill Chief of Police Edward Wrixon told Baker that cops, as a precaution, treated the incident as if a gunman was inside the building.

“We responded with our active-shooter program,” Wrixon said. “Two of our officers arrived first on the scene and immediately went into the school and started clearing hallways and securing school rooms.”

The regional SWAT team, Bergen County police and neighboring forces joined in the response. Police used K-9 units to perform security sweeps.

“We practice drills of marching the kids to a safe zone such as this, so this is nothing that we haven’t done already,” Wrixon said. “Unfortunately, we had to put it into play thinking that it was a serious and it was a legitimate threat.”

Parents received an emergency text message alerting them to the situation.

“I’m not frightened because the kids, they’re saying that they’re safe, and it’s just that they got an anonymous call,” said mother Nidhi Birani.

“This isn’t something you want to hear,” added mother Karen Hess. “It happens all too often unfortunately, but they’ve been really great with the communication.”

Students, however, were shaken by the incident.

“People were scared and nervous,” one girl said.

“Getting a text from my son, Robert, when it happened at 10:30, and all he told me was he was in the locker room (and) he was very scared,” Robert McCullen, a father, said.

Police say they will investigate whether there is a connection with incidents at four other districts in New Jersey on Monday.

 Cranford High School in Union County and neighboring Brookside Place School operated under a shelter-in-place order after the high school received a threatening phone call around 10 a.m., school officials said.

 At Indian Fields Elementary School in South Brunswick, an all-clear was given after students were evacuated due to reports of two possibly unauthorized people inside the building. Two city librarians were buzzed into the school but did not check in at the main office.

 Macopin Middle School in West Milford was placed on lockdown after a bomb threat was phoned in.

 Marlboro Middle School in New Jersey also received a phone call shortly before 1 p.m., which prompted an evacuation. Kids were taken to another location and then eventually dismissed early.

Meanwhile in Middleton, New York, Maple Hill Elementary School was placed on lockdown after a threat was called in there, police said.

Late Monday night, a bomb threat was also reported at St. Mary’s Hospital in Passaic – prompting search by authorities, the Bergen Record reported.

National school safety consultant Ken Trump said his Cleveland-based firm looked at 800 such instances in the first five months of school, WCBS 880’s Jim Smith reported.

“The majority turned out to be young people who are making very poor decisions, who view these threats as being a hoax, a prank,” he said.

But it’s no laughing matter.

“The threats and hoax incidents actually drain law enforcement resources,” Trump said. “They divert them from legitimate needs in the community.”

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