Moderate Muslims are powerless against the forces of Islamic fundamentalists who propagate anti-Semitism, a cleric of Manhattan’s largest mosque said yesterday.

“Extremists have taken initiative and have stepped to the center of the arena,” Imam Omar Abu-Namous said. “The Muslim nation is not able to stop them.”

The imam and the president of the Foundation for Ethnic Understanding, Rabbi Marc Schneier, participated in an interfaith dialogue in honor of the Reverend Martin Luther King Jr.’s birthday, which will be celebrated today.

During the conversation, held at the Islamic Cultural Center of New York on the Upper East Side, the imam said Islamic fundamentalism is not a religious problem but a political one that emanates from the Israeli-Palestinian Arab conflict.

His comments came in response to Rabbi Schneier, founder of the Hamptons Synagogue, who asked the imam if he would speak out against Muslims who advocate violence against Jews, and against those who deny the Holocaust. The rabbi in turn volunteered to participate in an international campaign to fight “Islamophobia.”

Imam Abu-Namous said Muslim teachings warn against extremism and that acts of fundamentalists do not represent his faith. “We do not believe them when they say they are acting in the name of Islam,” he said.

He added, “We are as much victimized as you are.”

Yesterday’s event was billed as the first time in the cultural center’s 16-year history that a rabbi came to speak at the mosque.

King’s son, Martin Luther King III, who addressed the gathering, praised the religious leaders for coming together in honor of his father. “There’s got to be more of this that takes place in the world,” Mr. King said.

Also in attendance was the hiphop mogul Russell Simmons, the chairman of the Foundation for Ethnic Understanding. Mr. Simmons, who is not Muslim, said the Reverend Louis Farrakhan of the Nation of Islam is a “great inspiration to me.”

Rev. Farrakhan, a black Muslim, is a controversial figure in the Jewish community because he has made repeated anti-Semitic comments and has accused Jews of wielding excessive power in the press and the economy.

Yesterday’s event was set up as conversation to help highlight what Judaism and Islam have in common. The moderators, a Jewish lay leader and a Muslim sheik, urged the panelists to focus on theology — not on the Israeli-Palestinian Arab conflict.