Republican presidential candidate Donald Trump called a protester wearing Ku Klux Klan hood a "disgusting guy" at a campaign rally in Tucson, Arizona.
A group of protesters were escorted out of the rally with one protester wearing what appeared to be a Ku Klux Klan type hood.
As the group of protesters were being escorted out, a person from the crowd appeared to push one of the protesters to the ground, punching and kicking them. The man was then arrested by the police, CBS footage showed.
Trump rallies have grown increasing unruly as the months-long campaign has progressed.
Trump, the favourite to win his party's nomination for the Nov. 8 presidential election, currently leads in opinion polls ahead of Arizona's March 22 primary, according to a Real Clear Politics polling average, leading Senator Ted Cruz of Texas by 13 percentage points.