Eight high school students in Parker, Colorado, posed for a prom picture with a large Confederate flag and guns, television station KDVR reported on Monday.

The students from Chaparral High School took the photo to commemorate their prom, which was held on Saturday in Denver. The group picture was snapped at a home and featured three boys in suits and five girls in fancy dresses. While the boys held the Confederate flag, two of the girls held guns.

The mother of one of the boys in the photo spoke anonymously to KDVR about the incident, saying the behavior displayed in the photo was unacceptable and explaining that her son made a mistake.

“When he got out there he was surprised that guns were brought out and the Confederate flag was brought out,” the mother said. “There were other parents there fully supporting it and taking pictures.”

“I think in their immaturity they kind of think it’s a sort of a cowboy type of thing but then to have parents that support it and feed into it and to explain that it borders on racism is really upsetting to me,” she continued.