An American frustrated by activists downplaying Hamas' brutal attack detailed the horrific massacres his family in the Israel Defense Forces have seen.

"Anybody who claims that this didn't happen is just denying the truth and is part of the problem and should be lumped together with the people of Hamas," Marc Tobin, who lives in Israel, told Fox News.

Some activists around the U.S. protesting the Hamas-Israel war have downplayed Hamas’ Oct. 7 attack that killed 1,400 Israeli civilians and soldiers and resulted in nearly 200 hostages. Anti-Israel demonstrators have called Hamas' massacres "resistance," accused Israel of genocide for carrying out retaliatory airstrikes in Gaza and been filmed ripping down posters of Israeli hostages.

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In response, Tobin, who has three sons and 13 nephews serving in the IDF, relayed his families' experiences. The IDF sent his middle son to the Gaza border last Monday to find terrorists still in Israel and to ensure survivors were accounted for in the nearby villages. He and his fellow soldiers went door-to-door in Kfar Aza.

"Unfortunately, they saw the massacre," Tobin said. "A lot of the bodies had been put into — already — body bags so they saw all the different sizes of bodies, the adults, the children and unfortunately, the infants."

Tobin said his son fortunately didn't see the bodies before they were put in bags, "but there were enough in his unit that did see that people were butchered."

body bags israeli soldiers

Israeli soldiers remove bodies of civilians who were killed days earlier during Hamas terrorists' attack in Kfar Aza, Israel. (Amir Levy/Getty Images)

Israeli Prime Minister Benjamin Netanyahu’s office last week released photos of babies that it says Hamas terrorists "murdered and burned" in Kfar Aza during the attack. More than 70 of the kibbutz's 765 residents were killed, according to the Times of Israel.

IDF troops found about 200 dead, including babies, some of whom they said were decapitated, Israeli media reported. 

"I think Hamas is just like the Nazis were," Tobin said.

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Tobin said protesters and activists ignoring Hamas' atrocities are taking a page out of Adolf Hitler’s chief propagandist's playbook to create and spread disinformation.

"[Joseph] Goebbels had a strategy of if you say it enough, then people believe it," he said.

At University of Massachusetts Amherst last week, over a hundred students turned out for an anti-Israel protest advertised as an event to stand in solidarity with Palestinians "breaking out of their open air prison." Another event outside Cambridge City Hall last week was promoted with text on a flyer that said "VICTORY IS OURS" and "LONG LIVE PALESTINIAN RESISTANCE."

Marc Tobin's four children

Marc Tobin's four children, including his three sons serving in the IDF. (Courtesy of Marc Tobin)

A New York City protester denied that any children were beheaded. An IDF commander told Fox News "There are a lot of men, women and children who have been beheaded."

"That's false. That is actually false," the protester told Fox News’ Lawrence Jones. "Israel is notorious for creating propaganda" so it can "massacre" Palestinians.

Israel's retaliatory attacks have killed about 3,500 Palestinians, including children and civilians, according to the Hamas-run Palestinian Health Ministry. It's unclear if that tally includes an explosion at a hospital that Palestinian authorities blamed on Israel, but U.S. intelligence independently determined was caused by another terrorist group.

Tobin praised the IDF for taking journalists to the massacre sites to get the truth into the press.

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"You can lie about anything, but the facts speak for themselves," he said. "There are people who will never believe that people can do that or they'll justify why they were able to perpetuate such a heinous crime." 

Protester shouting at Israel side

An anti-Israel protester in Cambridge on Monday shouted slurs at the pro-Israel counter-protesters, calling them "pigs" and "Nazis."  (Kassy Dillon/Fox News Digital)

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Tobin and his family moved from Boca Raton, Florida, to Israel 25 years ago. Two of his sons left their tech jobs to serve temporarily while the third delayed his start to college. He said they're "doing what they need to do."

Tobin had the opportunity to visit one son at his base.

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"I said thank you to a couple of soldiers for what they were doing," Tobin said. One said "'You don't have to thank me. We're fighting the Nazis and we're going to win.'"

"This is not 1935 and 1940 where the Jewish people had no way to defend themselves," Tobin added. "We have an army and we have people who are willing to drop everything else in their life to defend the homeland and to defend their families and to defend their people."

Isabelle McDonnell contributed to the accompanying video.