This year the ceremony, which has been held annually since 2006, was prerecorded to avoid the possibility of disruption by protesters. In previous years it attracted sharp criticism and a legal challenge in Israel, and on Sunday organizers said just before the ceremony was set to be broadcast that its website had been hacked. As a result, the organizers said it was not possible to watch it on YouTube as planned, and viewers instead watched on Facebook.

The ceremony, an annual focus for peace activists in Israel, featured speeches, songs, a poem about peace and a video that showed children in Israel and the Israeli-occupied West Bank talking about the effect of war. One child wished “for everyone who died to come back to life.” Palestinians in the West Bank did not participate in person, given that Israel stopped allowing many Palestinians to work in Israel after the Oct. 7 attacks led by Hamas, which the Israeli authorities say killed around 1,200 people. There were also no direct contributions by speakers in Gaza.

“For many Israelis it seems provocative,” Yuval Rahamim said of the ceremony in an interview by telephone from Tel Aviv. Mr. Rahamim, co-director of the Parents Circle — Families Forum, an Israeli-Palestinian organization of families who have lost immediate relatives in the conflict, said that his father had been killed in the 1967 Arab–Israeli War. He acknowledged that many Israelis would find the event jarring, given the scale of suffering on Oct. 7, but he said that also gave it more significance.

“Many people have woken up to the reality that this conflict cannot go on,” he said, referring to the decades of violence. “People are willing to stand up.”

His sentiment was echoed by Magen Inon, 41, whose parents were killed on Oct. 7 and who spoke in person at the start of the screening in London, which was held at a Jewish community center. He said that he did not want what had happened to his family to be used as an argument for further war. “We felt as if our personal pain is being hijacked by the national cause,” said Mr. Inon, who now works as a peace activist.

Many Israelis have argued the country is still bound by a sense of national shock and loss over Oct. 7. and are stunned by international criticism of the war in Gaza, which they mostly see as justified.

More than 35,000 people have been killed in Gaza during Israeli’s military campaign to defeat Hamas, health officials there say, and almost everyone there has been displaced from their homes amid a hunger crisis that aid workers say has been largely caused by Israeli restrictions on aid deliveries to the enclave.

But the ceremony, which was screened at more than 200 venues in Israel, spoke to the diversity and complexity of opinion within Israeli society about the issue. Several speakers discussed their hope for an end to generations of bloodshed, and for peace.

Among the most stark contributions came from Palestinian speakers who described conditions in Gaza.

Ghadir Hani read a contribution from a woman in Gaza, whose name was given only as Najla, describing how she had lost 20 family members in the war, including her brother, a father of two, who she said had been killed while going to look for food for his parents.

“They killed him while walking in the street though posing no threat whatsoever,” Ms. Hani read. “The death machine is still ready to kill,” she added. “But I know that on the other side there are many people who believe in peace.” Prime Minister Benjamin Netanyahu of Israel has repeatedly said that Israel’s war is with Hamas, rather than the people of Gaza, and that his government regrets civilian casualties.

Another contributor, Ahmed Helou, a member of Combatants for Peace, which gathers people who have fought either for Israel or for Palestinian groups, suggested that the ferocity of Israel’s campaign had forced him to reassess the personal cost of his commitment to peace.

“The Israeli army is still killing shamelessly. Everyone in Gaza is a terrorist in their eyes,” said Mr. Helou, as he recounted a litany of death his family had endured in Gaza. “Does causing unsurmountable pain promise peace for the Israelis?”

Israel’s Memorial Day began at sundown on Sunday and ceremonies will be held through Monday afternoon.