US presidential front-runners Hillary Clinton and Donald Trump maintained their leads in the race to secure their party's nomination after the latest primaries on Tuesday despite trading wins with their chief rivals.
While both Clinton and Trump scored victories in the night's biggest prize of Arizona, Democratic challenger Bernie Sanders won caucuses in Utah and Idaho and Republican Ted Cruz claimed his party's caucuses in Utah.
Trump's hardline immigration message proved to be successful in Arizona, which is one of the US states that borders Mexico. New York billionaire won the primary there with 47 percent of the vote and took all 58 delegates.
His closest rival, Texas Senator Ted Cruz won the other contest of the night, Utah presidential caucus and secured all 40 delegates by finishing with more than 50 percent of the vote.
Despite losing Arizona, the biggest state of the night, Sanders won more delegates than Clinton, 57 to 51, with big margin victories in Utah and Idaho.
Sanders said his Utah and Idaho victories were powered by young people and working-class Americans who support his "political revolution."
"These decisive victories in Idaho and Utah give me confidence that we will continue to win major victories in the coming contests," he said.
Former US Secretary of State Hillary Clinton is leading Sanders by more than 300 pledged delegates after Tuesday’s results.
The contests were overshadowed by attacks in Brussels in which at least 31 people were killed and raised security concerns among US voters.
Clinton seized on the Brussels attacks to argue that neither Trump nor Cruz can be trusted to lead the fight against DAESH.
Trump has called for a temporary ban on Muslims entering the United States and Cruz said he would send police patrols into Muslim neighborhoods in the United States.
"This is a time for America to lead, not cower," Clinton told supporters in Seattle in a victory speech.
"This is about not only selecting a president, but also selecting a commander in chief," Clinton said in Seattle as she condemned Trump by name and denounced his embrace of torture and hardline rhetoric aimed at Muslims. "The last thing we need is leaders who incite more fear."
Trump, in turn, branded Clinton as "Incompetent Hillary" as he discussed her tenure as secretary of state. "Incompetent Hillary doesn't know what she's talking about," the billionaire businessman said in an interview with Fox News. "She doesn't have a clue."
After his win Trump also reiterated his calls to party establishment to unite around him.
"Much bigger win than anticipated in Arizona. Thank you, I will never forget!" Trump said on Twitter. "Hopefully the Republican Party can come together and have a big WIN in November, paving the way for many great Supreme Court Justices!"
Overall, Trump has accumulated 739 delegates, Cruz has 465 and Kasich 143. It takes 1,237 delegates to win the GOP nomination.