(NewsNation) — Cities throughout the United States are bracing for protests on the first anniversary of the Oct. 7, 2023, Hamas attack on Israel.

Monday marks one year since Hamas and Palestinian Islamic Jihad, two militant groups backed by Iran, carried out an attack in which 1,200 people in Israel were killed and around 250 taken hostage.

Some events began over the weekend and additional protests and rallies are expected Monday.

Oct. 7 commemorative events

Several thousand people could attend a rally in Washington, D.C., that a Christian nonprofit organized in support of Israel. Leaders at Columbia University also issued a notice to students Monday, saying the campus could be the site of major gatherings for the anniversary.

The university campus has been home to several pro-Palestinian protests over the past few months. School staff said extra security will be on hand Monday and students may notice more dividers and barricades.

Some events began over the weekend, including thousands who marched through downtown Washington and gathered near the White House to show solidarity with Palestine. Crowds also gathered near Times Square in New York City, where some people waved Palestinian and Lebanese flags. Others protested against Israeli Prime Minister Benjamin Netanyahu.

The group If Not Now has called for an end to U.S. support for Israel and plans to host events in cities including Boston, Los Angeles and Chicago to honor lives lost during the war.

Antisemitic incidents reach fever pitch

Meanwhile, antisemitic incidents in the United States have reached an all-time, according to the Anti-Defamation League (ADL).

The group recorded more than 10,000 antisemitic incidents in the U.S., including bomb threats against synagogues, assaults against Jewish students on school campuses and online harassment.

That’s the most incidents ever recorded in a single year since the ADL began tracking that data in 1979. This year’s numbers are three times higher compared to the same period last year.

Many of those incidents have involved verbal or written harassment, but some included vandalism and physical attacks, according to the ADL.

“The attacks by Hamas, by Hezbollah and the Houthis and the direct onslaught by the largest patron of antisemitic terrorism, Iran, have sparked a fire here in the U.S. and throughout the world,” the ADL wrote in a post commemorating the anniversary. “While antisemitic incidents had already been on the rise, these attacks threw fuel onto the fire.”

Hamas said its attack was in response to the continued Israeli occupation of the Palestinian territories, the blockade of the Gaza Strip, the expansion of illegal Israeli settlements, threats to the status of the Al-Aqsa Mosque in Jerusalem and the plight of Palestinian refugees and prisoners.

The Israeli offensive in Gaza has caused widespread devastation and killed thousands, according to the Hamas-run Gaza Health Ministry.