Donald Trump touted new evidence to back his disputed 9/11 claim - but the people he cited are pushing back

Real-estate mogul Donald Trump is furiously defending his claim that "thousands and thousands" of Muslims celebrated in New Jersey as the World Trade Center buildings collapsed on September 11, 2001.

But the sources Trump and his campaign are citing as evidence are pushing back.

On Monday, Trump tweeted a link to a years-old video of Curtis Sliwa, an anti-crime activist and local media personality, saying that people had called his show about the supposed Muslim celebrations.

"Good job Curtis," Trump wrote, adding that the media fact-checkers who disputed his claim should send their apologies to his Twitter account.

Sliwa responded by accusing Trump of doctoring the video of him discussing the attack. Sliwa said the full video actually suggested that there weren't "thousands and thousands" of people partying in New Jersey as the towers went down.

"It was just a dozen teenagers," Sliwa told MTV News.

MTV News once did a detailed investigation on the Muslim-celebration rumors and only found evidence of a small number of kids running amok after being let out early from school.

"Quickly the adults came out, they disciplined them, they took them back into their homes," Sliwa said. "There was no repetition, no continuation thereafter."

Sliwa also demanded Trump apologize for taking his comments out of context:

On Tuesday, several Trump campaign accounts touted another piece of supposed evidence backing up Trump's claim about the World Trade Center attacks: an old CBS story that addressed allegations of eight people celebrating the attack.

Trump campaign adviser Dan Scavino said the report proved Trump "100% correct."

But the CBS reporter who was apparently quoted in the story, Pablo Guzmán, fired off a flurry of tweets at Scavino saying that his report was being misinterpreted. (A CBS News report confirmed the authenticity of Guzmán's Twitter account.)

"There were many such [anecdotes] circulating then. I went on air when law enforcement sources told me might be something," Guzmán wrote. "As I reported, my 'source' - actually, from Jersey City [Police Department], and also Port Authority [Police Department] - were told eight people seen."

In additional tweets, Guzmán stressed that the eight people who were being investigated was a far cry from the "thousands" claimed by Trump.

"Eight cheering is 8 too many. But not 'thousands.' And disgusted Muslims also called police about people on roofs," he continued. "Real life not usually black or white. Real life is complicated. Telling the truth can get difficult. But if you don't follow an agenda, it can get done."

A wave of media fact-checkers have disputed Trump's claim about September 11 since he first made it at a November campaign rally while making the case for surveilling mosques. But Trump has repeated the claim time and time again, even getting into an especially nasty spat with a New York Times reporter who said Trump was incorrect to cite his own years-old report.