Donald Trump on Sunday blamed Democratic presidential candidate Bernie Sanders of instructing his supporters to disrupt Trump rallies, and appeared to threaten to respond in kind.
Refusing to tone down the inflammatory rhetoric critics say is fueling the potential for dangerous violence, the Republican presidential frontrunner tweeted, "Bernie Sanders is lying when he says his disruptors aren't told to go to my events. Be careful Bernie, or my supporters will go to yours!"
His accusation came after a Trump rally in Chicago on Friday was called off amid scenes of violence that included fistfights and people throwing bottles in what many believe is a turning point in the campaign if not American politics.
Speaking on CNN later, Trump called protesters at his rallies "bad people that are looking to do harm to our country."
"When these people come into (my rallies), you know, everybody thinks I'm a bad guy," he said.
"If my people went into one of (Sanders's) rallies, they'd say, 'oh, this is a terrible thing.' They would be arrested and all sorts of things would happen to them."
Sanders on Sunday denied his campaign had directed supporters to protest Trump rallies.
"Trump's words must be taken with a grain of salt because I think as almost every knows, this man cannot stop lying about anything," he said, adding that Trump is inciting violence because poll numbers show he would not win a general election.
"People in America know that we cannot have a president like Trump who insults Mexicans, who insults women, who insults Muslims," he said, also on CNN. "People are catching on to Donald Trump. That's why he's getting reckless."
Other politicians across the political spectrum have called on Trump to tone down his rhetoric, saying he is fanning division by exploiting anger among the electorate.
Marco Rubio, his rival for the Republican nomination who is trailing in third place, called Trump's actions "reckless and dangerous."
"If we reach a point in this country where we can't have a debate about politics without it getting to levels of violence and anger," he told CNN, "we're going to lose our republic."
The exchanges come ahead of primaries and caucuses in five major American states on Tuesday, with Trump hoping to lock in the Republican nomination, in what is being billed as a referendum on his campaign.