The device exploded in a classroom, injuring the 16-year-old and four classmates nearby. School administrators called 911, the school was immediately evacuated, and students were transferred to the bus garage when emergency services arrived, police said.
All schools in Newaygo County were closed in accordance with the county’s contingency plan until authorities determined there were no further threats to students.
Based on the initial investigation, it appears that the student had no malicious intent and had no intention of detonating the device, Michigan State Police spokesman Michelle Robinson told CNN.
The 16-year-old was taken to hospital for moderate to severe injuries, while the four other students were taken to hospital by their parents for minor injuries. The class teacher also went to the hospital because the explosion caused smoke and there were concerns about the chemicals that may be used in the device, Robinson said.
“The investigation continues into what type of material was involved in the explosion and the circumstances that contributed to it,” said state police, adding that the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives were on the scene to assist in identifying the explosive materials involved.
CNN has reached out to Newaygo Public Schools for comment.
Correction: An earlier version of this story incorrectly identified which police department represents Michelle Robinson as a spokesperson. Robinson works for the Michigan State Police.