A Jewish organisation in the United States has slammed U.S. presidential contender Donald Trump after he claimed to have seen thousands of Arab Americans cheer when the Twin Towers collapsed on 9/11.

The Anti-Defamation League said on Sunday that Trump’s comment was “unfortunate.” “This seems a variation of the anti-Semitic myth that a group of Israelis were seen celebrating as the Twin Towers fell,” the ADL told Buzzfeed. “His comments are irresponsible — not to mention factually challenged.”

Trump said on Saturday that thousands of Arab Americans in Jersey City, New Jersey, cheered on Sep. 11, 2001 when the World Trade Center collapsed.

“I know it might be not politically correct for you to talk about it, but there were people cheering as that building came down -- as those buildings came down, and that tells you something,” Trump told ABC News. “It was well covered at the time."

Jersey City Mayor Steven Fulop reacted to Trump’s claim and said the presidential contender either distorted the truth wilfully or had “memory issues.” Either of the two should concern the Republican Party, he said.

According to Fulop, Trump is “shamefully politicising an emotionally charged issue.” The mayor stressed that no one in the city had cheered on 9/11. Trump should understand that Jersey City won’t be a part of his hate campaign, he added.

Almost 3,000 people were killed in the 9/11 attack, and the damage was worth around $10 billion (AU$13.9 billion). Some conspiracy theorists argues Muslims in the United States were seen cheering when the Twin Towers collapsed.

However, NY Times reported that the claim was no more than an Internet rumour which had been dismissed long back. Some people from the Middle East were seen cheering in a footage broadcast on television, but news accounts from the period show no reports of mass cheering in Jersey City.

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