Updated

A Colorado university has suspended a religious studies professor whose silent protest against racial bias led to complaints about his refusal to speak during classes.

Naropa University professor Don Matthews said he launched the protest on the Boulder campus during his classes last week, the Boulder Daily Camera reported Wednesday.

He said he walked around with a piece of paper explaining his protest and answered questions during the last 10 or 15 minutes of his classes to make sure students understood their assignments.

Matthews, who is black, said he filed a complaint with the U.S. Department of Education's Office for Civil Rights after several other African-American faculty members and administrators left the university. Matthews cited bias and racism at the school. He could not be reached for further comment by The Associated Press.

Naropa President Charles Lief told the newspaper that administrators had received more than 30 complaints from students against Matthews in the past 18 months.

Lief also said the suspension had nothing to do with Matthews' race. However, he acknowledged the university has work to do on issues of diversity.

"If this was a completely random set of circumstances and facts, and nobody had a clue if the faculty member was male, female, African American, white, whatever, we would have taken the same steps," Lief said. "We're not looking for him to leave. We want him to stay."

Lief was not immediately available for further comment to the AP.

He told the newspaper that 17 percent of Naropa students identify as students of color, which includes African-American students, Native-American students, Hispanic students and those who identify as mixed race.