This story has been updated.
Schools in eight Bergen County school districts and one in Passaic in New Jersey and three other states were lockdown Tuesday morning after threats were received.
Bomb threats also were reported at seven school districts in the Boston area as well as in Delaware and Iowa.
None of the threats were found to be valid.
In New Jersey, Dwight Morrow High School in Englewood, Clifton, Hackensack, Teaneck, Tenafly, Bergenfield, Fair Lawn Garfield and Leonia all received threats. Law enforcement sources said the threats all appear to have come from the same phone.
"It appears that all stemmed from an automated message," said Anthony Cureton of the Bergen County Sheriff's Office.
County prosecutor's detectives were investigating.
Schools in those districts were either lockdown or shelter in place.
K-9 unites from Bergen and Passaic counties swept the schools.
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