Republican front-runner Donald Trump has easily won New York's presidential nominating contest, moving closer to capturing enough delegates to win the nomination and avoid a contested convention in July.
The New York City billionaire's big victory in his home state gave him renewed momentum in the Republican race and pushed him closer to the 1237 delegates needed to win the nomination.
Democratic front-runner Hillary Clinton also won in New York, which she once represented in the US Senate, blunting the momentum of rival Bernie Sanders and taking a big step toward wrapping up the nomination.
The victories for Mr Trump and Mrs Clinton in one of the biggest state nominating contests so far set up both front-runners for strong performances next Tuesday, when they are expected to do well in five other north-eastern state primaries.
Mr Trump had more than 60 percent of the vote with about 40 percent counted, easily beating rivals Ted Cruz, a US senator from Texas, and Ohio Governor John Kasich and putting him in position to possibly win most or all of the state's 95 delegates.
Mr Trump could win all of the delegates if his vote total is above 50 percent statewide and in each of the state's congressional districts.
"We don't have much of a race anymore based on what I'm seeing on television," Mr Trump told cheering supporters at a victory party at his Trump Tower in Manhattan. "We are really, really rocking."
Mr Trump entered the New York contest with 756 delegates, while Mr Cruz had 559 and Mr Kasich had 144, according to an Associated Press count. The count includes endorsements from several delegates who are free to support the candidate of their choice.
Mr Trump said his New York win would make it almost mathematically impossible for Mr Cruz to win the Republican nomination on the first ballot at the party's national convention in July.
Mr Cruz, Mr Kasich and establishment forces in the party have been trying to keep Mr Trump from winning on the initial ballot.
If Mr Trump does not secure enough delegates needed to win the nomination on the first ballot at the 18-21 July conclave in Cleveland, delegates would be allowed to switch to other candidates.
Mr Trump remains unpopular with the Republican leaders and activists who select and serve as delegates, while Mr Cruz has invested time and money courting them.
Some establishment Republicans have been alienated by Mr Trump's more incendiary proposals, such as building a wall along the border with Mexico and slapping a temporary ban on Muslims entering the country.
Mrs Clinton's win in New York followed some of the most heated personal exchanges of her campaign against Sanders, a US senator from Vermont who had won seven of the last eight state-by-state nominating contests.
The New York victory will expand Mrs Clinton's lead of 244 pledged delegates over Mr Sanders, and make it nearly impossible for him to overcome the deficit and capture the 2383 convention delegates needed for the nomination under Democratic rules that allocate delegates proportionally based on each state's result.
The voting in New York was marred by irregularities, including more than 125,000 people missing from New York City voter rolls. The city has roughly 4 million voters considered active for the primaries.
New York City Comptroller Scott Stringer ordered an audit of the city elections board after it confirmed the names had been removed from voter rolls. He told the board in a letter it was "consistently disorganized, chaotic and inefficient".
"It is absurd that in Brooklyn, New York, where I was born actually, tens of thousands of people as I understand it have been purged from the voting rolls," Mr Sanders told supporters at a rally in State College, Pennsylvania.