US Republican front-runner Donald Trump has called off a rally in Chicago on safety grounds after protests led to violent clashes, reports the BBC.
A statement from Mr Trump's campaign said the candidate decided to cancel the event after a meeting with police.
Hundreds of protesters gathered outside the venue at the University of Illinois hours before Mr Trump was due.
Inside the auditorium, fighting broke out between supporters and protesters, who waved flags and chanted.
There were chants for Mr Trump from his supporters and for Democratic candidate Bernie Sanders from some of the protesters.
There were several violent clashes, some sparked by Trump supporters attempting to wrestle flags from protesters.
One protester had to be physically removed from the stage by what appeared to be a Secret Service agent.
Violent clashes continued outside the venue, with helicopter footage showing chaotic scenes as police attempted to control the large crowds.
The full statement from Mr Trump's campaign read: "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."