The government of Israel will take the extraordinary step of sharing raw video recovered from Hamas terrorists who slaughtered more than 1,400 of its citizens on October 7 in an effort to tamp down what it called a “Holocaust denial-like phenomenon evolving in real time” by people “casting doubt on the magnitude of the atrocities that Hamas committed against our people.”

A spokesman for the Israeli government, Eylon Levy, said in a video posted to Twitter late Sunday that the government will screen the video Monday for foreign journalists “who can stomach the horrific truth and want to report on what they saw.”

“Unfortunately, and I can’t believe I am saying this and I can’t believe that we as a country are having to do this,” he says in the video. “The government press office will screen for foreign media, gruesome and as yet unseen footage of the barbarities perpetrated against our people on October 7.”

Mr. Levy said the video was recovered from the bodies of Hamas terrorists who slaughtered as many as 1,400 people, including women and children, and took hundreds of others hostage two weeks ago. The video has not yet been seen by the public, he added, and was recorded by the terrorists in order to glorify the violence.

Across Europe on Sunday, hundreds of thousands of protesters took to the streets of major cities to protest the war. Some marched in support of Israel, others to decry the ongoing war in Gaza.

In London, thousands of people holding posters with the images of the more than 200 Israelis and other nationals still being held by Hamas in Gaza filled Trafalgar Square for a vigil calling for their release. The United Kingdom’s communities secretary, Michael Gove, was among those who called the attacks an act of “unparalleled evil and barbarism,” according to the Associated Press.

“We must stand together against it. We must stand for life. We must bring the hostages home,” Mr. Gove said.

A day earlier, however, a much larger crowd — estimated by police to be up to 100,000 — marched through the British capital to demand that Israel halt its war against Hamas. Those marching could be heard praising “Jihad,” or holy war, and proclaiming “from the river to the sea, Palestine will be free” and referring to Israel as a “terrorist state.”

For the second consecutive weekend, similar protests filled the streets of Europe’s capitals, among them Rome, Berlin, and Paris. Police officials put the pro-Palestinians crowd in Paris — where authorities banned such protests earlier in the week — at nearly 15,000.

Despite widespread reports from survivors and the anguished testimony of those charged with recovering and identifying the victims of Hamas’ massacre, social media and other online forums have been filled with claims that Israel is exaggerating the extent of the depravity it witnessed two weeks ago.

Experts at Israel’s National Center for Forensic Medicine, known as Abu Kabir, are said to have been overwhelmed with emotion this week as they described parents and children being tied together before being set on fire while still alive, babies and others beheaded, and widespread signs of torture of the victims before they were murdered.

Reaction to the Israeli government’s plans to release footage of the attacks veered from grudging acceptance of the necessity of the move in order to counter propaganda from Hamas and their sympathizers in the West to dismay and concern for the families of the victims.

“So this is what it has come to,” the chairman of the Spectator magazine and a prominent British television presenter, Andrew Neill, posted on Twitter shortly after Mr. Levy’s announcement. “The only way to confront and refute the deniers of the Hamas Holocaust on October 7 is to show Hamas’s own footage of their barbarity on that terrible day. So be it.”