(Reuters) - A U.S. judge overseeing lawsuits accusing Harvard University of antisemitism on Tuesday narrowed but refused to dismiss a case by two advocacy groups accusing the Ivy League school of making it unbearable for Jewish students to study there.

U.S. District Judge Richard Stearns said the Louis D. Brandeis Center for Human Rights Under Law and Jewish Americans for Fairness in Education can pursue a hostile educational environment claim on behalf of students.

The Boston-based judge dismissed claims that Harvard directly discriminated against Jewish and Israeli students, and retaliated against them for complaining about antisemitism.

A lawyer for the plaintiffs had no immediate comment. Harvard and its lawyers did not immediately respond to requests for comment.

In August, Stearns refused to dismiss a related lawsuit by Jewish students who accused Harvard of letting its Cambridge, Massachusetts campus become a bastion of rampant antisemitism.

Both lawsuits accused Harvard of violating Title VI of the Civil Rights Act of 1964, which bars federal funds recipients from allowing discrimination based on race, religion and national origin, and sought to stop further violations.

Tuesday's decision primarily concerned Harvard's alleged mishandling of incidents from the spring and fall of 2023.

In one, a Jewish lecturer at Harvard's Kennedy School allegedly pressured students in a course on organizing community action to abandon a project predicated on the existence of a "liberal-Jewish democracy," because associating "Jewish" with "democracy" created an "unsafe space" for classmates.

The other concerned a viral "die-in" near Harvard Business School where attendees accused Israel of war crimes, chanted antisemitic slogans and allegedly physically assaulted an Israeli-Jewish student.

Stearns said the plaintiffs can try to prove Harvard's "deliberate indifference" to harassment, reflecting its failure to discipline the professor and alleged lack of speed investigating various incidents.

"To conclude that the mere act of launching an investigation without any further follow-through necessarily defeats a deliberate indifference claim, would be to prioritize form over function," Stearns wrote.

Stearns nonetheless found no plausible accusations that Harvard's responses reflected anti-Jewish or anti-Israeli animus, or retaliation.

The lawsuits are among many accusing major universities of allowing and encouraging antisemitism following the October 2023 outbreak of war in Gaza between Israel and Hamas.

(Reporting by Jonathan Stempel in New York; Editing by Bill Berkrot)

By Jonathan Stempel