CLIFTON, N.J. (AP)- Bomb threats were made against schools in at least nine New Jersey towns Tuesday, and now authorities believe they are part of a pattern that stretches up and down the East Coast.



None of the threats was considered valid, but schools in Garfield, Bergenfield, Leonia, Fair Lawn, Englewood, Teaneck, Hackensack, Tenafly and Clifton, N.J. received the robocall threats overnight. Police are investigating whether they are related.



Some schools were evacuated, while others instituted lockdowns on Tuesday.



Clifton Police Department spokesman Robert Bracken said the high school received a voicemail saying that a bomb had been placed in one of the schools and there was going to be a mass shooting. Other schools received similar threats.



Bracken said there's no indication the threat was real, but precautions were taken.



In addition to the threats in New Jersey, 15 were made in Massachusetts, three in Delaware, two in Maryland and one in Pennsylvania.



The FBI said it is aware of the situation, and that the incidents are being handled by local law enforcement partners.