More than 20 students at a Virginia high school were suspended Thursday after wearing clothes depicting the Confederate flag.

The students wore the offensive attire in protest of Christianburg High School’s ban of the emblem. Twenty-five students arrived at the school violating the Confederate flag ban, according to Montgomery County Public Schools spokeswoman Brenda Drake. Twenty-one of the 25 students refused to comply when challenged by school officials and were issued one-day, in-school suspensions.

The school bans students from wearing clothes that oppose diversity and acceptance. This year, the district banned Confederate flags on students’ vehicles.