The Trump administration is reviving an investigation into allegations of anti-Semitism at Rutgers University, where Jewish students said they were charged a discriminatory fee in 2011 to attend a campus event critical of Israel’s policy toward Palestinians.

With its action, the Education Department cited a definition of anti-Semitism that encompasses certain expressions of anti-Israel sentiment. Observers said it appeared to mark a shift in civil rights enforcement on matters related to the Middle East conflict that often prove controversial on college campuses.

The Obama administration closed the Rutgers case in 2014 without finding wrongdoing by the university.

But Kenneth L. Marcus, assistant education secretary for civil rights under President Trump, said in a recent letter that the 2011 incident at the public university in New Jersey merited further scrutiny in response to an appeal from the Zionist Organization of America.

Marcus said the department relies on a working definition of anti-Semitism from the International Holocaust Remembrance Alliance as investigators evaluate charges of discrimination against Jewish students.

Among examples in that definition, cited in Marcus’s Aug. 27 letter, are “claiming that the existence of a State of Israel is a racist endeavor”; applying a double standard to Israel by requiring of it “behavior not expected or demanded of any other democratic nation”; and comparing “contemporary Israeli policy to that of the Nazis.” The letter was disclosed last week by the Zionist Organization of America, an advocacy group.

The Zionist group hailed the department's action. "This definition accurately addresses how anti-Semitism is expressed today; it recognizes that Jew-hatred can be camouflaged as anti-Israelism or anti-Zionism," the group said in a statement.

Pro-Palestinian groups denounced the move. “Marcus is sending a clear signal that attacking free speech for Palestinian rights is at the top of his agenda,” Dima Khalidi, director of Palestine Legal, a group that defends activists, said in a statement. “This is a perverse use of government resources."

Marcus, who won Senate confirmation to his position in June, has led the independent Louis D. Brandeis Center for Human Rights Under Law. That nonprofit group seeks to combat anti-Semitism on college campuses. He has spoken out against academic boycotts targeting Israel, describing one in 2016 as “arguably anti-Semitic.” Marcus also led the Education Department’s civil rights office during the George W. Bush administration.

Elizabeth Hill, a spokeswoman for the department, said Wednesday that the federal agency has not adopted a definition of anti-Semitism. Hill said the department enforces federal law prohibiting discrimination on the basis of race, ethnicity or national origin. Within that context, she said, allegations of anti-Semitism at schools may draw scrutiny.

"The facts in the Rutgers case, many of which were disregarded by the previous administration, are troubling," Hill said.

Rutgers said in a statement that it had not received notification from the department of the reopening of the investigation. But it pledged to cooperate. “There is no place for anti-Semitism or any form of religious intolerance at Rutgers,” the university said.

At issue was an event held by pro-Palestinian and anti-Zionist groups at the New Brunswick campus on Jan. 29, 2011, titled “Never Again for Anyone.” It was advertised as free and open to the public. But witnesses told federal investigators that a $5 fee was imposed for entry before the event started.

The circumstances behind the fee are the subject of debate. The university later determined that sponsors were seeking to control attendance because the event had drawn a larger-than-expected crowd, including many who were not students, according to a federal summary of the incident in July 2014.

The Zionist group alleged that the fee was selectively applied to block Jewish and pro-Israel students from the event. Federal investigators who interviewed witnesses found no evidence, according to the 2014 federal summary, that Jewish people who paid the fee were denied entry or that non-Jewish people who refused to pay the fee were let in. The investigators concluded there was insufficient evidence to substantiate that imposing the admission fee was discriminatory. They also found insufficient evidence to determine that the university mishandled the matter during or after the event.

Four years later, Marcus decided to revisit the case. He cited an email from the time of the incident in which an organizer of the event said the admission fee was needed because "150 Zionists just showed up," although "if someone looks like a supporter, they can get in for free."

Marcus wrote that the email and other witness information raised questions about how event organizers defined and recognized Zionists.

"In cases such as this, it is important to determine whether terms such as 'Zionist' are actually code for 'Jewish,'" he wrote.

Reopening the seven-year-old case will also put a federal spotlight on the Rutgers of today. Marcus wrote that federal investigators will look at whether a “hostile environment” exists at the university for students of “actual or perceived Jewish ancestry or ethnic characteristics.”

Laura Meckler contributed to this report.