WESTFIELD, NJ — Students and staff at Edison Intermediate School went back to their routines after a  lockdown Wednesday morning, Superintendent Dr. Margaret Dolan said in an email to parents Wednesday afternoon.

“Edison students and staff are safe. Westfield Police are investigating a reported incident,” Dolan wrote. “A brief lockdown was initially called but has been lifted. Students are returning to their regular schedule.”

Parents later received an email from Principal Matt Bolton saying that at no time was a threat made against the school.

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The lockdown was called after police received a “concerning phone call in the vicinity of Edison School,” he wrote. The lockdown was lifted after police determined the source of the call and that the call was a prank, the email said.

Edison parents said that their children were under the lockdown for more than an hour.