STURGIS, S.D. — A South Dakota high school has forfeited its homecoming football game against a school from a nearby American Indian reservation and has cancelled its homecoming dance and parade after photos posted on social media show students destroying a car with "Go back to the Rez" painted on the side.

Sturgis Brown High School was scheduled to play Pine Ridge School, from the Pine Ridge Indian Reservation, on Friday. On Thursday, the Meade School Board voted 8-0 to cancel all remaining activities to avoid the potential that students could be put in danger, the Rapid City Journal reported.

Sturgis Principal Pete Wilson told The Associated Press that he learned of the posts Wednesday evening, saying the actions of a few reflect poorly on the school and that the situation "hurts the student body."

"It's the worst day I've ever had," said Wilson, adding that discipline would occur "after we figure out everything."

Superintendent Don Kirkegaard said: "I can't defend those actions, but I can try my best to make sure it never happens again." He said the district is working with police to determine who was responsible.

Pine Ridge Principal Michael Carlow commended Kirkegaard for taking responsibility and for his efforts to address the issue.

A photo shows people hitting a car with sledgehammers. The ritual used to be homecoming tradition but is no longer sponsored by the school, according to the newspaper.

Sturgis Police Chief Geody VanDewater said the department is working with school officials to provide assistance. VanDewater added that "at this point there's not anything criminal," but police are "looking through it thoroughly before we make judgment."

Kirkegaard, the school board and the district's administration and staff apologized for the actions of a "few students" from the high school in a joint statement, the Rapid City Journal reported .

"We do not support, teach nor endorse the inappropriate behaviors and actions that occurred Wednesday evening. We are appalled and disgusted by the racist comments that appeared on social media," the statement said.

Wilson said there was an assembly Thursday morning at the school, which state fall 2016 enrollment numbers say had about 685 students. Wilson said officials are planning cultural awareness assemblies throughout the entire district.