Chaos broke out at a peaceful protest in Salt Lake City over the weekend when gunfire rang out during a “No Kings” demonstration, sending two people to the hospital and prompting a swift police response that led to three arrests.

According to Salt Lake City Police, officers heard shots Saturday night where a massive crowd of protesters had gathered. One person was critically injured in the shooting and rushed to a nearby hospital.

The suspected gunman, who had reportedly been walking with the crowd before the violence erupted, also sustained a gunshot wound and was taken into custody after officers tracked him down. He remains hospitalized.

Roughly 10,000 demonstrators had marched from Pioneer Park to the Federal Building as part of the nationwide “No Kings” movement, defending immigrant rights, and pushing back on what they called an erosion of democracy under President Trump.