US presidential hopeful Donald Trump called off a rally in Chicago on 11 March after violent clashes erupted between protesters and supporters of his campaign. Several hundred demonstrators packed an arena at the University of Illinois hours before Trump was due to appear there, with some of them getting into physical confrontations with backers of the Republican front-runner.
Clashes were also reported outside the arena as police scrambled to restore order.
Trump's campaign said in a statement that it had decided to postpone the event after holding discussions with Chicago police.
"Mr Trump just arrived in Chicago and after meeting with law enforcement has determined that for the safety of all the tens of thousands of people that have gathered in and around the arena, tonight's rally will be postponed to another date," the statement read.
"Thank you very much for your attendance and please go in peace."
The Associated Press news agency reported that demonstrators, who accuse Trump of divisive politics and stoking racial tension, broke out into raucous cheers after hearing that the rally had been called off.
"Trump represents everything America is not and everything Chicago is not," student Kamran Siddiqui, 20, told AP.
"We came in here and we wanted to shut this down. Because this is a great city and we don't want to let that person in here."
The clashes in Chicago came 48 hours after a man in North Carolina was arrested for assaulting an African-American protester at a Trump rally in that state.
Speaking to Fox News, Trump said he made the decision to postpone the rally because he "didn't want to see people get hurt".
"What we did was intelligent — a very good decision... a wise decision," he stated.
"If we had the rally, I think it would not have been a good situation. Our First Amendment rights have been violated."
Trump is leading the Republican presidential pack ahead of next week's primaries in Ohio, Illinois, North Carolina and Florida.
He has run a controversial presidential campaign in which he has proposed building a wall on the US-Mexico border to keep out illegal immigrants, along with temporarily barring Muslims from entering America.
Earlier on 11 March, Trump's candidacy was publicly endorsed by his former rival Ben Carson, who retains large support among evangelical voters.
"He is actually a very intelligent man who cares deeply about America," Carson, 64, said at a press conference in Palm Beach, Florida.
"There's two different Donald Trumps. There's the one you see on the stage, and there's the one who's very cerebral, sits there and considers things very carefully."