Knox County Schools administrators have said they have “received a number of nonspecific threats over the last couple of days” after the school shooting in Florida.

According to school officials, law enforcement have investigated all of the threats and have found “nothing credible."

A former student went on a shooting rampage at Marjory Stoneman Douglas High School in Parkland, Fla., on Wednesday afternoon in one of the deadliest high school shootings in modern American history.

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At least 17 people were killed and 14 were injured and taken to local hospitals, officials said.