The threat of violence against a school in Brooklyn Park on Thursday has been linked to a string of harassing and prank calls made against schools across the country.
Brooklyn Park police provided an update on Friday, after the threats made on Thursday forced Park Center High School and Brooklyn Park Middle to go into lockdown.
The lockdown was eventually lifted during the afternoon, with police finding no credible threat to student safety.
Detectives later discovered after serving several search warrants that the number from which the threat was made was not a local one.
It has subsequently "been linked to other national complaints of harassment and pranks."
"This case remains under investigation as detectives continue to try and identify the individual who made the threatening phone call," the department said.
A quick Google News search reveals reports of several threats made at schools across the country on Thursday.
Threats and lockdowns were reported in locations including San Diego, California; Mesa, Arizona; Ocoee, Florida; and Scranton, Pennsylvania.