The unnamed students were wearing the custom-made shirts at last weekend's Springfest and photos spread quickly once they were posted to social media. The school's Fighting Sioux nickname and Indian head logo were retired in 2012, but the issues surrounding them remain.
"I just don't understand how someone could be that ignorant to think something like that is acceptable, and if that really is the case where they really are that ignorant and it never crossed their mind once, it speaks to the issues at this university," former Indian Studies Association Treasurer Dani Miller wrote on Twitter, according to the Grand Forks Herald.
The UND Fighting Sioux logo was deemed "hostile and abusive" by the NCAA and 68 percent of North Dakota voters cast their vote to get rid of it.
"The message on the shirts demonstrated an unacceptable lack of sensitivity and a complete lack of respect for American Indians and all members of the community," UND President Robert Kelley said in a statement. "UND has a responsibility to promote respect and civility within the campus community, and we have the responsibility and right to speak out against hateful behavior."
The website that printed the shirts, CustomInk.com, also issued an apology.
"We are very sorry about this offensive design. CustomInk's business is focused on bringing people together in positive ways," the company said in a statement. We apologize for any pain or offense caused by this shirt, and we will continue to improve our review processes to make them better."
UND cannot select a new nickname until 2015.
Swim Week Miami Beach 2014 [PHOTOS]