The Hill City School near Grand Rapids, Minn., was closed Thursday while law enforcement investigated anonymous threats made on social media to the school and some students.

Hill City Superintendent Pat Rendle said he began getting calls about 11:30 p.m. Wednesday from some coaches, concerned parents and school board members alerting him to threats made on Snapchat and Facebook.

The threats related to an incident that took place last week involving a student, Rendle said. The anonymous source or sources of the messages said they were going to come to the school Thursday and shoot some specific students who were interviewed about last week's incident, he said. Rendle declined to say more, citing privacy restrictions.

"They were naming a student and saying they were going to take revenge on certain students," Rendle said of the messages.

The threatening messages were sent directly to the targeted students, who reached out for help. The messages, Rendle said, "were kind of direct and personal."

The school, about 13 miles south of Grand Rapids, has about 300 students in pre­kindergarten through 12th grade.

Rendle said he and school board members decided to close the school as police investigate after considering what took place Wednesday at schools in Orono, in the western suburbs of Minneapolis. There, students and staff barricaded doors after social media posts threatened a school shooting, and the schools were placed on lockdown. A student was arrested, and classes resumed Thursday.

"I don't know that we get to think these things don't matter, because words matter," Rendle said.

The incident in Hill City is under investigation by the Aitkin County Sheriff's Office, Hill City police and the Minnesota Bureau of Criminal Apprehension. The Aitkin County sheriff said in a prepared statement that more information will be made available "when it is appropriate." Anyone who received a threat or who has information about the threats is asked to call 218-927-7400 or 1-888-900-2138.

Dan Browning • 612-673-4493