A Donald Trump rally in Chicago had to be called off on Friday evening amid scenes of violence and chaos unparalleled in the recent history of American political campaigning.

The scrapping of the Republican frontrunner’s appearance due to what his campaign cited as “safety concerns” led to uproar and fights inside the University of Illinois Chicago Pavilion and in the streets outside.

Confrontations shut down Trump rally in Chicago - in pictures Read more

Scuffles broke out between Trump supporters, protesters and police, and a number of arrests were made, including of at least one reporter. As the mayhem took hold, Trump was reduced to complaining about the situation on the air, telling MSNBC: “It’s sad when you can’t have a rally. Whatever happened to freedom of speech?”

The rally had been due to take place at a university that is one of the most diverse in the country, at a venue situated in the heart of Chicago, a Democratic stronghold where there are few registered Republicans.

Before the rally was even due to start, the scene for the evening was set as protesters inside the pavilion vented their opposition to the presidential candidate’s positions on immigration, race and other issues where his rhetoric has proven divisive.

The shouts on both sides were often crude and vulgar. Trump supporters yelled “Go back to Univision” at Hispanic people and hurled a racially charged insult at an African American woman; while those opposed to the candidate shouted “Fuck Donald Trump” and taunted police officers.

Facebook Twitter Pinterest Protesters celebrate after it is announced that the rally has been cancelled. Photograph: Chicago Tribune/Rex/Shutterstock

Police walked up and down the arena stairs holding sheaves of plastic handcuffs amid fraught but as yet non-violent scenes. Attendees grabbed signs from each other’s hands and several dozen people were ejected from the event long before formalities were scheduled to begin. At least one section of young people was cleared out by police long before the event began, including many of Middle Eastern appearance. “Just because I look like them doesn’t mean I’m with them,” said one.

Then it was announced that Trump wasn’t coming – and the arena erupted into chaos.

College students shouted “We shut it down” while loyal supporters of the Republican frontrunner shouted “We want Trump”.

Fights and scuffles broke out as protesters swapped blows with Trump supporters and activists eager to celebrate their apparent victory shouted “Bernie, Bernie” and “Si se puede” (“Yes we can”), while waving signs supporting the Democratic candidate Bernie Sanders.

Facebook Twitter Pinterest Trump supporters and protesters clash outside the UIC Pavilion after the rally was cancelled. Photograph: Chicago Tribune/Rex/Shutterstock

After the postponement was announced a Trump campaign statement said: “Mr Trump just arrived in Chicago and after meeting with law enforcement has determined that for the safety of all of the tens of thousands of people that have gathered in and around the arena, tonight’s rally will be postponed to another date.

“Thank you very much for your attendance and please go in peace.”

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Despite Trump’s statement that he had consulted law enforcement, the Chicago police department emphasised it had no involvement in the decision.

There is a growing catalogue of violence at Trump events. In the past week alone an attack on a non-violent protester led to criminal charges against a Trump supporter, and Michelle Fields, a reporter for conservative website Breitbart, was allegedly assaulted by Corey Lewandowski, Trump’s campaign manager.

Trump’s rhetoric has done little to keep it in check. When the Republican frontrunner appeared in St Louis earlier on Friday, for an event that entailed more than 30 arrests, he complained: “Part of the problem and part of the reason it takes so long [to kick protesters out] is nobody wants to hurt each other any more.” Trump added: “There used to be consequences. There are none any more. These people are so bad for our country. You have no idea folks, you have no idea.”

Much of the violence after the Chicago cancellation was concentrated around a parking garage adjacent to the University of Illinois Chicago Pavilion. Protesters crowded the sidewalks, pushing at barricades formed by police as they tried to block Trump supporters’ cars from leaving.

Facebook Twitter Pinterest A Trump supporter reacts to protesters inside the UIC Pavilion. Photograph: Scott Olson/Getty Images

A spontaneous blockade of a parking garage formed, creating a standoff between screaming Trump supporters in the multi-level lot and screaming protesters on the ground below.

From high up Trump supporters reportedly spat down on protesters who were chanting “Fuck Donald Trump” and preventing anyone leaving. Eventually, after police cleared a path for people to depart, protesters jeered and gestured at each car and its occupants making their way past barricades and a long column of mounted police.

In the parking garage afterwards, Nerijus Meskauskus, a Trump supporter from Oak Lawn, Illinois described being assaulted by protesters. He told the Guardian that he had been holding an American flag and smoking a cigarette with fellow Trump supporters after the rally when someone came up and grabbed the flag. As Meskauskus described it, he was surrounded by protesters and punched “six or seven times” before “cops grabbed me and pulled me over the barricade”. He said protesters were “trying to jump the barricade to attack me”.

The scenes of violence sparked condemnation for the tenor of Trump’s campaign from his top rival for the GOP nomination, Senator Ted Cruz of Texas. “A campaign bears responsibility for creating an environment,” said Cruz. “The predictable consequence of [Trump’s comments] is it escalates. Today is unlikely to be the last such instance.”

Facebook Twitter Pinterest A protester burns a Trump campaign flag outside the venue. Photograph: Jonathan Gibby/Getty Images

The Ohio governor, John Kasich, took a similar line. “Tonight the seeds of division that Donald Trump has been sowing this whole campaign finally bore fruit, and it was ugly.”

Marco Rubio, the Florida senator, had harsh words for the protesters, telling Fox News there was “an industry” of protest movements in Chicago with some participants “probably being paid to do this.”

Political violence on the scale witnessed on Friday is rare in American politics.

Trump campaign dogged by violent incidents at rallies Read more

Famously the 1968 Democratic National Convention in Chicago witnessed repeated clashes between the police and anti-war protesters culminating in what a federal commission called “a police riot”.

But the three-way conflict between Trump supporters and protesters with the police caught in the middle is something unusual and represents a disturbing trend in an election where many of the norms and mores of American politics have gone by the wayside.

Facebook Twitter Pinterest A demonstrator in St.Louis, Missouri, explains to Donald Trump supporters why the term ‘all lives matter’ is dismissive to the black community.

In the meantime, the protesters had succeeded in their goal for the evening. As one, Violet Ornelas, 28, gleefully told the Guardian: “If he can’t even handle Chicago, what makes him think he could handle Isis?”