Threats of violence Friday at Oak Creek High School have resulted in an increased police presence at the school this week.
In a letter to parents, Superintendent Sara Burmeister said the threat is not considered credible, but the Oak Creek Police Department is taking it seriously and investigating.
"This rumor has raised considerable anxiety among parents, coming as it does right after the unfathomable horror of the tragic shootings in Connecticut and while the shooting at the Sikh Temple is still fresh in our minds," Burmeister said.
"Please know that our administrative staff and our police department have all been responding to and investigating all information regarding the threat, which appears to be circulating primarily through social networking/media."
Those who provided false information or tried to generate more threats face "significant consequences," Burmeister said in the letter, which is also posted on the district's website.
Similar threats for Friday—the Mayan calendar's end of the world—have been made in other school districts in southeastern Wisconsin.