Supporters, protesters clash outside Donald Trump's rally in Utah

Salt Lake City: Protesters clashed with supporters of Donald Trump after he gave a speech in Utah , ending a day full of presidential candidate appearances that also saw Mitt Romney intensifying his criticism of the Republican front-runner.

Hundreds of people chanted "Dump Trump" and "Mr. Hate Out of Our State" as police in riot gear blocked the entrance to the Salt Lake City building, after protesters tried to rush the door and got into dozens of screaming matches with Trump supporters who didn't make it into the venue for yesterday night's rally.

Trump was in Utah to campaign ahead of Tuesday's caucuses with 40 delegates at stake. The main event Tuesday for Republicans will be the Arizona primary in which the winner will take all 58 delegates to the party's national convention in July that will choose the nominee.

Trump's main rivals, Texas Sen. Ted Cruz and Ohio Gov. John Kasich, are desperately trying to prevent the real estate mogul from accumulating the 1,237 delegates needed to secure the nomination on the first ballot at the convention, giving added importance to each state contest.

Early polling shows Cruz leading among Utah's predominantly Mormon voters, but Trump is expected to win Arizona's primary where many Republicans support his call for building a wall along the border with Mexico and mass deportations of immigrants living illegally in the US.

A number of Republican officials have shown their support for Cruz in recent days while falling short of endorsing the senator, an uncompromising conservative.

In his first public appearance of the campaign in Utah, Trump said he loves Mormons but had critical words for 2012 Republican presidential candidate and Utah resident Mitt Romney, who said he was supporting Cruz in the state's caucuses.

"Are you sure he's a Mormon? Are we sure?" he jokingly asked his crowd at the Infinity Event Center. The announcement from Romney, the faith's most visible member, dealt a blow to Kasich as he campaigned in the heart of Mormon country.

Kasich brushed off the endorsement, telling reporters yesterday in Orem that Romney is entitled to his opinion that voting for Cruz could deny Trump the Republican nomination.

But the Ohio governor said the election "is not a parlor game," and he contends that he is the Republican best suited to defeat Democratic front-runner Hillary Clinton in November.

Clinton's sweep of five state contests last Tuesday gave her a nearly insurmountable lead in delegates over Vermont Sen Bernie Sanders.