A prominent national private schools group has apologized for remarks some speakers made at a conference about diversity and inclusion earlier this month, after leaders of several Jewish organizations condemned the comments as antisemitic.

The speakers, whose remarks were recorded, characterized Israel’s war in Gaza as a genocide and the establishment of the state of Israel as a racist project. They were addressing an annual gathering of students and educators held by the National Association of Independent Schools, which includes about 1,700 private schools across the United States, including 60 Jewish day schools. The event, known as the People of Color Conference, has been held for nearly four decades and focuses on helping schools create inclusive communities.

Some of New York City’s most prestigious private schools sent delegations to the conference, including the Dalton School on Manhattan’s Upper East Side, which sent 48 administrators, faculty and staff members, according to its website.

The leaders of several Jewish groups, including the Anti-Defamation League, denounced the remarks in an open letter to the association sent last Wednesday. Citing complaints from attendees, the letter described the atmosphere at the conference, held in Denver from Dec. 4 to Dec. 7 and attended by about 8,000 adults and students, as “toxic.” Some Jewish students were frightened, the letter said, to the point that some who were wearing Star of David jewelry felt compelled to hide it.

“No student should ever be made to feel this way because of their identity,” said the letter, which was signed by the A.D.L.’s chief executive, Jonathan Greenblatt, as well as three chief executives of prominent Jewish groups, Paul Bernstein of Prizmah: Center for Jewish Day Schools; Ted Deutch of the American Jewish Committee; and Eric Fingerhut of the Jewish Federations of North America.

In response to the criticism, Debra Wilson, the association’s president, issued an apology and said that future speakers’ addresses would be vetted. “That any student would feel the need to conceal their identity at our conference is antithetical to our mission and our values,” Ms. Wilson wrote.