Police said a fight broke out between two girls during the ninth-grade first lunch period, and the school resource officer tried to intervene. A boy tried to interfere with the officer, who then radioed for police assistance.
Several other fights broke out and at least nine other students were detained. Police used pepper spray to break up the fight.
One student is in police custody and investigators are checking into charges for others.
One student was taken to the hospital with a minor injury. No weapons were believed to be involved in the fight and no other injuries were reported.
Order was later restored and classes resumed Tuesday. Muskegon Superintendent Jon Felske said parents were later informed of the incident.