Anti-Trump protestors rally in New York, Arizona

Demonstrators briefly shut down an Arizona highway ahead of a campaign rally for US president hopeful Donald Trump while protesters rallied outside of Trump Tower in Manhattan to voice their opposition to the front-runner for the Republic presidential nomination.

Television news footage of the demonstration outside Phoenix showed dozens of protesters blocking traffic while holding signs that read "Dump Trump" and "Shut Down Trump."

The demonstrators eventually started marching down the highway. Later, some were seen nearing the rally at Fountain Hills, Arizona, before Trump arrived.

Three people were arrested, according to police in Maricopa County, where Joe Arpaio, a well-known critic of U.S. immigration policy and an ardent Trump supporter, serves as sheriff.

Tempers flared at the rally itself, but without the violence that marred Trump’s event in Chicago a week earlier. A handful of people were arrested, police and witnesses said.

Later at a rally in Tucson, Arizona, Trump said the protests were "disgraceful," and thanked police.

"They arrested three people and everybody else left... They left!" Trump said to roaring cheers from the audience.

"I love our police, but we should do a little bit more of that, you'd have a lot less protesters, you'd have a lot less agitators," said Trump, who is favoured to win his party's nomination for the Nov. 8 presidential election.

Several demonstrations also broke out during the later rally, prompting police to escort out a number of people.

In Trump's home city of New York, about 1,000 demonstrators marched from Central Park to Trump Tower, the billionaire developer's signature building on Fifth Avenue.

The crowd of mostly young people chanted and carried placards denouncing Trump. Some said police used pepper spray on them as they marched from the park.

Police were seen taking at least one person into custody. A spokesman for the New York Police Department could not immediately confirm whether any arrests were made or whether pepper spray was used.

Trump leads in opinion polls ahead of Arizona's March 22 primary, according to a Real Clear Politics polling average, leading Senator Ted Cruz of Texas by 13 percentage points.