Trump, speaking at a rally in Columbus, OH said he has received “hundreds” of phone calls and tweets from people who claim to have seen the celebrations.
"Lo and behold I start getting phone calls in my office by the hundreds, that they were there and they saw this take place on the internet," Trump said in Ohio.
Trump also quoted from the Sept. 18, 2001 Washington Post article which described how authorities detained people "allegedly seen celebrating the attacks and holding tailgate-style parties on rooftops while they watched the devastation on the other side of the river."
Trump told ABC News' George Stephanopoulos that "there were people that were cheering on the other side of New Jersey where you have large Arab population."
"They were cheering as the World Trade Center came down," he added. "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. It was well covered at the time."
The mayor of Jersey City said Trump was "plain wrong."
"It’s not true," Marco Rubio said today in Iowa. "And there’s plenty of fact-checks to prove that it isn’t."