ALBUQUERQUE, N.M. (AP) — The mother of two Native American teenagers who police pulled from a Colorado State University campus tour after another parent said she was nervous about their presence is calling the incident "shameful on so many levels."

Lorraine Kahneratokwas Gray told The Associated Press Thursday that her 17-year-old and 19-year-old sons saved money to travel to the school in Fort Collins.

She stayed behind in New Mexico.

She says her older son called her frantic during Monday's encounter, saying "somebody called the police on us because we were quiet."

Campus officers spoke to the brothers and released them. Their tour group had moved on.

The university called the case "sad and frustrating" in a campus email and is reviewing how similar incidents can be avoided or handled better in the future.