An armed student is holding a classroom hostage at a high school in Wisconsin, with no immediate reports of injuries or shots fired.

Police say a gunman has released five students after he took 23 students and one teacher hostage in a classroom at Marinette High School, Police Chief Jeff Skorik said Monday evening. Police know the identity of the suspect and are trying to reach his parents.

Police also have been in communication with the teacher inside the classroom, Skorik said. She confirmed that she and the students were being held hostage at gunpoint, but Skorik didn’t elaborate on the details of her communication with police.

Negotiations were not yet under way with the suspect, he said.

A school administrator reported the hostage standoff at the end of the school day, 3:48 p.m. local time Monday, saying the student burst into the classroom and took hostages.

Choral teacher Bonita Weydt said she was talking with a teacher in another classroom after school, which lets out about 3:10 p.m., when principal Corry Lambie came in.

“I said, ‘Corry, what’s going on?’ and he said, `Get out of the building,”‘ Weydt said.

Parents were asked to respond to the county courthouse to receive information on their children.

Marinette is about 50 miles north of Green Bay and sits on the border with Michigan’s Upper Peninsula. The high school has an annual enrollment of approximately 800 students, according to its website.