SIOUX FALLS, S.D. (AP) -- North Dakota school administrators are investigating a photo posted to Twitter from Friday's state hockey semifinal game in which three fans in the student section are wearing Ku Klux Klan-style white robes and hoods.
Shane Schuster, 19, said he was seated with some friends at Ralph Engelstad Arena when something in the Red River High School student section across the rink caught his eye midway through the first period.
"I thought, `Are those KKK hoods?' I couldn't believe it," he said. "I was shocked."
Schuster, a University of North Dakota student, said he focused his camera phone and snapped a photo, later uploading it to Twitter. The hoods were on for about 10 to 20 minutes, he estimated, but they were removed by the second period.
Mark Rerick, the Grand Forks Public Schools' athletics director, said Saturday that he conferred with arena and tournament security staff immediately after learning about the picture.
"After confirming the incident, we notified the administrators at Red River High School who immediately began their investigation," Rerick said in a statement emailed to The Associated Press. "To the best of my knowledge, the students have been identified by the Red River administrators who are continuing their investigation."
Schuster said Red River's principal contacted him Saturday asking if he had any additional photos, but he had just one.
Red River topped Fargo's Davies High School 2-0 to advance to Saturday night's North Dakota Boys State Hockey Tournament title game against Grafton-Park River.
Davies High School is named in honor of Ronald Davies, the former federal judge from Fargo whose 1957 rulings integrated Central High School in Little Rock, Ark. - a pivotal event in the civil rights movement.
The photo that Schuster posted on the social media site shows the three hooded fans in the middle of the Red River Roughriders section, in which everyone is dressed in white as part of a "whiteout." The post had been retweeted more than 50 times by Saturday afternoon, with many users expressing their outrage.
The hockey tradition of encouraging fans to all wear all white was started more than 25 years ago by the original Winnipeg Jets - which currently are the Phoenix Coyotes. In 1987, Jets fans donning white shirts and jerseys packed Winnipeg Arena to watch the team take on the Calgary Flames in the first round of the Stanley Cup playoffs.
The practice has since spread to the college and high school levels.