While police investigate the origin of the threats, security has been stepped up at all station houses following the fatal shooting of two NYPD officers.
American Airlines Flight 67 from Barcelona had about 200 passengers on board when it safely landed around noon.
County police said the school calls came in within 15 to 20 minutes of each other, and their bomb technicians and K-9 units were dispatched to investigate.
Authorities were sweeping high schools in Garfield, Hackensack, Englewood and Fort Lee on Wednesday, as well as three school buildings in Leonia.
An Israeli citizen and A Hoboken man were both arrested Sunday for allegedly making separate false bomb threats at Newark-Liberty International Airport.
New York area synagogues were on heightened alert Monday, and some New York City apartment buildings were taking the extra precaution of not accepting package deliveries at all.
In the tri-state, synagogues are seeing a heavier police presence as the packages in Friday’s bomb plot were addressed to synagogues in Chicago.