BROOKINGS (AP) - The Brookings School District has closed all schools for the day after a written threat of violence was found at the high school.

The district said in an announcement on its website that it was closing to "allow for collaboration" with the police department. All school-related activities also were cancelled.

Officials say a note was found at the end of the school day Monday, but the nature of the threat was not released. Parents were notified Monday night through phone calls.