US Republican front-runner Donald Trump and Democratic favorite Hillary Clinton swept to victory in Arizona on Tuesday as states in the American West weighed in on the 2016 presidential race.
Trump, the anti-Washington figure who has riled establishment Republicans, easily defeated his two rivals for the Republican presidential nomination, US Senator Ted Cruz of Texas and Ohio Governor John Kasich, US television networks projected.
On the Democratic side, Clinton stretched her advantage in the Democratic contest by winning Arizona, routing US Senator Bernie Sanders of Vermont.
The contests in Arizona and Utah were overshadowed by attacks in Brussels that left at least 30 people dead, and added to security concerns that American voters have expressed to pollsters.
Long lines of voters were reported in both states.
Trump, the New York billionaire and former reality TV star, has ridden an anti-Washington message to become the favorite for the nomination. This has left a flagging anti-Trump effort with faint hopes of stopping him at the Republican national convention in July.
In Arizona, which is one of the US states that borders Mexico, Trump's hardline immigration message is popular and he leads in polls, while in Utah Trump lags in polls behind top rival Ted Cruz, a US senator from Texas.
Arizona will award its entire slate of 58 delegates to Trump.