NORTHFIELD -- Hundreds of students have packed an administration building for a protest at St. Olaf College as students boycott classes to protest recent racist incidents at the school in the southern Minnesota town of Northfield.

The latest incident happened Saturday when a woman found a note with a racial slur on her car. The note demanded that she "shut up or I will shut you up.''

Speakers have been demanding that the private Lutheran liberal arts college adopt a policy of zero tolerance for racism.

The St. Olaf administration has released a statement saying hateful and threatening messages such as the one found Saturday are unacceptable. They say an active investigation is under way. They say someone, somewhere knows who's responsible and asked for help in identifying the individuals involved.