The Clarkstown Police said on Twitter the schools were put on lockdown around 3 p.m., Thursday, Nov. 21.
Department officials said they were working with other law enforcement agencies to conduct a search of the school and have since lifted the lockdown.
Officers will remain on the scene until all buses leave the school, and then parents will be allowed to pick up their students, the department said.
The department had said earlier Thursday that they received a report of a possible threat phoned in around 11 p.m., Wednesday, Nov. 20, to a crisis hotline. The caller claimed to be a student from the school, police said.
A check by police found that the name and all of the information provided by the unidentified male did not match the database of the Clarkstown School District, the department said.
Before the lockdown, the department said they were investigating the incident and were in contact with the School District.
"Additional patrols are at the school as a precaution," the department said earlier. "There has been no credible evidence of any imminent threat to the school or the students. We will continue to investigate this incident and will remain in contact with school administrators."
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