Republican U.S. presidential candidate Donald Trump (C) speaks as rivals Marco Rubio (L) and Ted Cruz listen during the Republican U.S. presidential candidates debate sponsored by CNN at the University of Miami in Miami, Florida March 10, 2016. REUTERS/Carlo Allegri

Donald Trump’s Republican rivals for the White House condemned protests that shut down his planned Chicago rally on Friday, but said his aggressive speech was partly to blame.

The thousands of protesters who showed up for Trump’s rally Friday evening at the University of Illinois at Chicago turning it into a chaotic scene as they scrapped with his supporters. A half hour after the rally was slated to begin, a Trump campaign staffer announced it was being postponed for safety reasons, unleashing competing chants of “We dumped Trump!” and “We want Trump!” throughout the packed venue.

In statements to the press, candidates Ted Cruz and Marco Rubio both described the incident as “sad” and said the people who chanted anti-Trump slogans and fought with Trump’s fans inside a stadium at the University of Illinois should have respected the candidate and let the rally happen.

But they added that Trump shared some responsibility.

Trump has drawn fervent support on one side and harsh criticism on the other after he called on building a wall along the U.S.-Mexico border and imposing a temporary ban on Muslims entering the country.

Asked by CNN interviewer Don Lemon if he would take back anything he had said, Trump said: “Now, getting back to before tonight, when I talked about illegal immigration, I have no regrets whatsoever.”

“If I didn’t bring up illegal immigration, it wouldn’t even be a subject of the campaign,” he added.

His rallies often attract small groups of protesters, but Friday’s was the first at which there may have been as many protesters as supporters.

The two sides shouted at each other until a Trump campaign staffer appeared and announced the event would be postponed until an unspecified date for security reasons. After the cancellation, Trump appeared in a rally in St. Louis, Missouri earlier on Friday during which protests forced the front-runner to halt his speech repeatedly.

“Go home to mommy,” Trump said as security personnel ejected one of the protesters in St. Louis.

“When you have a campaign that affirmatively encourages violence,” Cruz, the Texas senator, said, “you create an environment that only encourages this sort of nasty discourse.”

In Chicago, while activity inside the rally was generally peaceful, a group of protesters gathered nearby clashed briefly with police when they tried to shut down an expressway, a Chicago Police Department spokesman said.
Two police officers were injured; one required stitches, according to the spokesman. A reporter for CBS News was arrested and later released, according to media reports.

The millionaire brash blamed on Saturday organized “thugs” for protests that shut down his Chicago rally and said the incident had “energized America.”

“The organized group of people, many of them thugs, who shut down our First Amendment rights in Chicago, have totally energized America!”, Trump said on Twitter.

Trump has a significant lead in primary contests over the three remaining Republicans competing for the White House, and he is looking to bolster it on Tuesday when voters in five more states, including Illinois, go to the polls.

Ohio Governor John Kasich, also battling Trump for the Republican presidential nomination, said the protests occurred because “the seeds of division that Donald Trump has been sowing this whole campaign finally bore fruit.”

Rubio, the Florida senator, had the harshest words for the protesters. He said in a Fox News interview protests in Chicago had become “an industry” and some of the people involved were “probably being paid to do this.”