BOULDER, Colo. A Colorado university has suspended a religious studies professor whose silent protest against racial bias on campus led to complaints that he refused to speak during classes.

Naropa University professor Don Matthews said he launched the protest on the Boulder campus during his classes last week. He said he walked around with a piece of paper explaining his protest and later answered questions during the last 10 or 15 minutes of his classes to make sure students understood their assignments.

According to the Boulder Daily Camera, Naropa officials said the silent protest was unnecessary, and they acknowledged that the university has work to do on issues of diversity. School officials said they want to resolve the issues and they want Matthews to resume teaching next year.