CABARRUS COUNTY, N.C. -- The Federal Bureau of Investigation is assisting local authorities after all Cabarrus County high schools were dismissed early following an anonymous threat Thursday.

According to the Cabarrus County Sheriff's Office, early indications were that the threat did not appear credible, but out of an abundance of caution, the decision was made by police and administrators to dismiss all students early.

"All CCS high school campuses will be dismissing early today as a precautionary measure in response to an unspecified threat," Cabarrus County Schools said Thursday.

Dismissals began immediately after the statement was issued around 11 a.m.

J.N. Fries Middle was also dismissed early as a "precautionary measure", according to Cabarrus County Schools.

Concord Police said multiple law enforcement agencies are investigating a threat. While they said the threat was not credible, schools are closing out of an "abundance of caution."

Cabarrus County Sheriff Brad Riley issued a statement, saying there are no further specific details about the threat, but that it did include "explosive devices."

"This is a coordinated decision between law enforcement and the school system," Concord Police said.

Following an investigation, officials gave the all clear around 1:30 p.m. Thursday.