Oct. 7 (UPI) — Solemn events across Israel to mark the anniversary of Oct. 7 were interrupted by Hamas rocket fire early Monday timed to coincide with the moment one year ago when 3,000 Hamas-led gunmen broke out of Gaza and rampaged across southern Israel in an orgy of killing, torture and rape.

The Israeli military said it had prevented a larger rocket barrage Monday with pre-emptive airstrikes on the launch sites in southern Gaza ahead of ceremonies and rallies, many of them unofficial, commemorating the attacks that left 1,200 Israelis dead and saw 251 people taken hostage.

Flags on government buildings flew at half-mast and a minute’s silence was observed by many, including TV and radio stations, at 6.29 a.m. — the moment Hamas began launching hundreds of rockets into Israel as covering fire ahead of their incursion.

Thousands of people traveled south to attend events in and around communities near the border with Gaza that were razed to the ground by Hamas and four other armed Palestinian groups.

Israeli President Isaac Herzog joined survivors and family members of the 360 young people killed at the Nova dance party, commemorating the anniversary at a huge impromptu memorial that has been erected at the site.

However, the anniversary also exposed wide divisions in Israel with hundreds of relatives, friends and supporters of about 99 hostages still being held in Gaza protesting in Jerusalem outside the home of Prime Minister Benjamin Netanyahu, whom they accuse of not doing enough to get the hostages released.

A year on from the deadliest assault in Israel’s 75-year history its overwhelming military response in Gaza aimed at “fully defeating” Hamas has killed 41,909 people and 97,303 injured, according to Gaza’s Hamas-run health ministry.

The United Nations’ humanitarian affairs office marked the anniversary of the “horrific” attack saying it has presaged what it said was “a year of unimaginable suffering,” and renewed its calls for a cease-fire and for U.N. member states to ensure international humanitarian law and International Court of Justice rulings were complied with.

Acting Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Joyce Msuya said it had been 12 months of “unrelenting tragedy” that must stop and that members must use their influence to work “to end impunity [of Israel].”

She said an immediate cease-fire and a “durable peace” to end the “physical, mental and societal devastation” were long overdue.

“We know what must happen: The hostages must be released and treated humanely. Civilians must be protected and their essential needs met. Palestinians arbitrarily detained must be released,” Msuya said.

“Humanitarian workers must be safeguarded and their work facilitated. Perpetrators must be held accountable for any serious violations of international humanitarian law. And the assault on Gaza must stop.”

U.S. President Joe Biden marked the anniversary by reiterating security assurances he made in an October 2023 visit to Israel shortly after the attacks in which he told Israelis “you are not alone.”

“One year later, Vice President Harris and I remain fully committed to the safety of the Jewish people, the security of Israel, and its right to exist,” Biden said in a statement released by the White House.

“We support Israel’s right to defend itself against attacks from Hezbollah, Hamas, the Houthis, and Iran,” he added, referencing the U.S. military coming to the aid of Israel in a successful joint-defense operation against Iran’s Oct. 1 ballistic missile attack.

Biden said that the hostages and their families had “been through hell” and that they were in his thoughts on Monday the 7th and every day, pledging to continue to work toward a cease-fire deal to free them and permit a humanitarian aid surge to ease Palestinians’ suffering.

He also condemned what he called a “vicious” rise in anti-Semitism in the United States and around the world, calling for people to unite against it and hate in whatever form it took.

Vice President and Democratic Party candidate for president Kamala Harris, pledging “unwavering commitment” to Israel’s defense, said she would never stop fighting for the release of the hostages and to prevent anything like the “horrors” of Oct. 7 from ever happening again.

“I will always ensure Israel has what it needs to defend itself against Iran and Iran-backed terrorists like Hamas,” she said in a statement.

“I will do everything in my power to ensure that the threat Hamas poses is eliminated, that it is never again able to govern Gaza, that it fails in its mission to annihilate Israel, and that the people of Gaza are free from the grip of Hamas.

“I will never stop fighting for the release of all the hostages, including the seven American citizens, living and deceased, still held,” Harris’ statement, added, referring to the Americans by their first names.