DENVER (WASHINGTON POST) - Two Native American brothers had saved up their money and pointed the family van north, rolling seven hours from Santa Cruz, New Mexico, to Fort Collins, Colorado.

Thomas Kanewakeron Gray, 19, and his brother Lloyd Skanahwati Gray, 17, Native Americans from the Mohawk tribe, were heading to check out the campus of Colorado State University. Both were not just interested in attending - CSU was their dream school, their mother would later say.

But the brothers did not receive the warm welcome they were expecting.

"It is one of their first experiences out in the real world and they run into this cruel world," their mother, Lorraine Kahneratokwas Gray, told the Denver Post this week. "That's why we have to speak out. My sons need to find the courage of speak out."

The brothers' time in Fort Collins got off to a bad start. They got lost in the new city, eventually arriving 30 minutes late to a scheduled campus tour for prospective students on Monday. Then as the group was moving through the campus gymnasium, campus police officers approached the pair of shaggy-haired teenagers, demanding to know what they were doing on campus, the Associated Press reported.

The brothers had reportedly unnerved another parent on the tour, making the individual "nervous". The parent called the police to report the suspicious pair. "Apparently, a parent on the tour called police because they were too quiet. That made them suspicious," their mother told the Denver Post.

"They were trying to listen. Why should it be a crime to listen and not engage in a conversation?"

The campus officers who arrived patted the brothers down. They were only released after showing an email demonstrating they had signed up for the tour. But the campus group had already moved on across campus. The Gray brothers never linked back up to finish the tour. Instead, they jumped back in their van and headed home.

"I was shocked. I was like, 'What are you talking about? That doesn't even make sense,'" their mother told Denver 10. "All because some biased person judged my boys on how they looked." The school quickly apologised to the Gray family and issued a letter to the student body.

"This incident is sad and frustrating from nearly every angle, particularly the experience of two students who were here to see if this was a good fit for them as an institution," the school wrote.

The Grays' day at CSU has further resonance for the Fort Collins campus. According to the Coloradoan, last fall a noose was found on campus. Nazi propaganda was distributed on campus during the school year. In February, violent protests greeted a controversial conservative campus speaker.

The CSU incident comes after a raft of similar situations have thrown a spotlight on racial bias and perceptions in the last weeks. In April, two young black men ended up in handcuffs after the manager of a Philadelphia Starbucks called the police. Another pair of black men were wrongfully arrested at a New Jersey L.A. Fitness gym after they were accused of not paying.

Both incidents fastened national attention on racial profiling, and the Gray brothers feel their own run-in at CSU fits into the same pattern.

"I think it's pretty discriminatory," Thomas, a current student at Northern New Mexico College who had been thinking about transferring to CSU, told the Associated Press. "Me and my brother just stayed to ourselves the whole time. I guess that was scaring people - that we were just quiet."