WASHINGTON (AFP) - Protesters opposed to Mr Donald Trump hurled rocks and bottles outside a rally in New Mexico on Tuesday, the same day the billionaire won the Republican presidential primary in Washington state.
The primary victory brings Mr Trump, the last Republican standing in the 2016 US presidential race, one major step closer toward clinching his party's nomination.
But the success was clouded by violent anti-Trump demonstrations in Albuquerque, New Mexico.
Chaos erupted outside a Trump rally when protesters threw burning T-shirts and bottles at police, and tried to storm the convention centre where the provocative Republican candidate was speaking.
Horse-mounted police and officers wielding clubs used pepper spray and smoke bombs to try to disperse the crowd.
The protesters, several of whom waved Mexican flags, chanted expletives about Mr Trump. Some also waved signs with expletive-laden anti-Trump slogans in Spanish.
Mr Trump has proposed building a wall on the Mexican border, suggested that Mexican immigrants were rapists and drug dealers, and urged the deportation of the 11 million undocumented immigrants in the United States.
"Protestors are now throwing bottles and rocks at our Police Horses," Albuquerque police tweeted.
The south-western US state has highest percentage of Hispanic residents - nearly 50 per cent - of any other state, and polls show that Hispanics overwhelmingly oppose Mr Trump's immigration proposals.
He addressed a rally of about 4,000 people earlier Tuesday evening, but was frequently interrupted by protesters, the Albuquerque Journal reported.
Police managed to stop a group of about 100 protesters who had tried to storm the convention centre when Mr Trump was speaking, the newspaper said. Riot police were deployed soon after.
Several Trump rallies have drawn protests, including in Chicago in March when his supporters clashed with protesters.
Mr Trump has been criticised for inciting violence at his rallies.
US networks called the race in Washington state for Mr Trump shortly after polls closed at 8.00pm (11.00am Wednesday Singapore time).
With more than two-thirds of ballots counted, Mr Trump earned 76 per cent of the vote.
"Thank you Washington! #Trump2016 #MakeAmericaGreatAgain," the candidate wrote on Twitter.
Mr Trump is the Republican Party's presumptive nominee, and while he is not officially the flag bearer yet he is on the cusp.
He headed into the race in the north-western state with 1,189 delegates, according to a CNN tally, just 48 delegates short of the 1,237 needed for the nomination.
Washington state has 44 delegates up for grabs. Mr Trump will therefore cross the threshold and clinch the nomination on June 7, when California and four other states vote on the final day of the Republican primary contest.
The real estate mogul's former rival, Texas Senator Ted Cruz, as well as Ohio Governor John Kasich and retired neurosurgeon Ben Carson, were still on the Washington ballot even though they had already dropped out of the race early this month following Mr Trump's decisive win in Indiana.
Mr Trump, a political neophyte whose provocative campaign has turned American politics on its head, will be officially installed as the Republican presidential nominee at the party's national nominating convention in Cleveland, Ohio in July.
He pivoted to the general election weeks ago, relentlessly criticising his likely Democratic rival Hillary Clinton.
The former secretary of state has returned fire, although she is still engaged in the final stages of her Democratic battle against challenger Bernie Sanders.
The senator from Vermont has an extremely narrow path to the nomination, and the math clearly favours Clinton.
Washington held its Democratic primary in March, and Mr Sanders won it easily. But Mrs Clinton, like Mr Trump, is close to becoming her party flag bearer.
