Fights involving protesters erupted Wednesday night outside a University of Minnesota building where a politically conservative speaker from Canada appeared, a school spokesman said.

Police sprayed a chemical irritant three times on some of the 200 to 250 or so protesters outside “to break up fights,” said university spokesman Evan Lapiska. No injuries were reported.

One person was arrested for disorderly conduct, Lapiska added. Court and jail records identified her as Brittany P. Cusack, 21, of Minneapolis. She was cited for disorderly conduct and left the jail in the middle of the night after posting $78 bail.

Protesters carried banners with “Minnesota against white supremacy” and “Bigotry not allowed.”

The speaker, Lauren Southern, 22, later tweeted to university police, “Thank you so much for defending free speech.”

The author, activist and internet personality spoke on the “Evils of Socialist Authoritarianism and Necessity of Free Speech.”

Her talk was hosted by Collegians For a Constructive Tomorrow Minnesota. The campus group describes itself as believing that “most consumer and environmental problems can best be met and overcome — not through excessive government regulation and bureaucracy — but rather, by better unleashing the power of the free-enterprise system and the ingenuity of science and technology.”

Star Tribune staff writer Brandon Stahl contributed to this report.