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Donald Trump said he wants to start "pressing charges" against protesters after the Republican presidential frontrunner's Kansas City rally on Saturday was repeatedly interrupted by demonstrations.

The controversial candidate blamed "bad, bad people" for the disruptions, which came just a day after fights between Trump supporters and protesters erupted in Chicago.

"I hope these guys get thrown in jail — they’ll never do it again," Trump said on Saturday. "It’ll destroy their record, they’ll have to explain to mom and dad why they have a police record and why they can’t get a job. And you know what? I’m going to start pressing charges against these people."

"I don’t want to ruin people’s lives. But the only way we’re going to stop this craziness is if we press charges," he added.

Related: Trump Supporters Weigh In on Violence at Rallies

It isn’t clear what charges Trump might be referring to.

Trump — who was repeatedly interrupted during his speech at the Midland Theatre — accused Bernie Sanders supporters of being behind the protests and had them removed.

Outside the event, police used pepper spray two times on demonstrators, Kansas City police said. Four people were arrested but there were no serious injuries of property damage, police added.

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As you can see, we were far from what happened and were not involved but he in walked up spraying us pic.twitter.com/f22WB5FAAG — Chris (@stokith) March 13, 2016

Kansas City Police Chief Darryl Forté said on Twitter "most in downtown area lawfully expressed themselves while lawfully assembling." He said a "fogger" was used on two large groups "preparing to fight."

Though Trump claimed he spoke to police and "they said why don’t you cancel," the police chief said later that he was "not aware of any discussion about cancelling the event."

It was after Trump cancelled an event in Chicago on Friday over what he said were security concerns that chaotic scenes broke out, with scuffles and fistfights inside and outside the University of Illinois at Chicago Pavilion.

There was more drama on Saturday when a man attempted to get on stage at a rally in Ohio and sparked a security scare — then the latest protests in Kansas City.

"These are bad, bad people, and we’re going to take our country back from these people," Trump told the crowd amid chants of "USA! USA!"

Trump has come under mounting criticism — from Democrats and from Republican rivals — for failing to fully denounce violent incidents at his events and for creating a climate where such incidents can persist.

Those issues were amplified in recent days after video emerged of a man at a Trump rally sucker-punching a protester leaving an event in North Carolina and after a Breitbart reporter accused Trump's campaign manager grabbing her hard enough to cause a bruise. The campaign manager has denied the claim.

Trump himself has said he would like to punch a protester in the face and see another taken out on a stretcher.

On Saturday, he urged security to treat protesters "gently."

"See, I’m a non violent person, did you know that about me?" he told the crowd and dismissed the protesters inside the theater as supporters of Sanders, the Democratic presidential hopeful.

Related: Trump Blames 'Thugs' For Violence at Postponed Chicago Rally

The Sanders campaign has denied involvement in the protests.

One Sanders supporter among the crowds on Saturday night was Matt McCann.

A self-described “big fan of the open marketplace of ideas,” McCann said he came to “look and to listen” but not to cause trouble.

“Eventually Donald Trump’s ideas are going to lose,” he said. “We just have to let them lose.”

He said Trump’s remarks about arresting protesters ran contrary to what “this entire country is about,” saying that nonviolent protest is important.

“Someone needs to be here pushing back,” he told NBC News.