Burnsville High School was placed on “modified” lockdown Wednesday after a morning altercation between students, the school announced.
Students followed their regular class schedules, but movement about the school was restricted while classes were in session.
The school also had an increased police presence for the rest of the day.
Six students were suspended Wednesday in what school officials describe as an altercation away from school the night before that spilled over into school Wednesday morning. No weapons were involved, the school said.
One student suffered a bruise to the face, School District 191 spokeswoman Ruth Dunn said.
The modified lockdown allowed authorities to calm the school, making it easier to investigate the incident, she said.
“Students were not in danger because of this incident with this group,” Dunn said.
Principal Dave Helke sent a phone message about the incident to parents Wednesday morning.