Washington ? The largest annual gathering of American Muslims began Friday with prayers for victims of Sept. 11 and for Muslims who have been harassed since the attacks.

Muhammad Nur Abdullah, president of the Islamic Society of North America, said in his opening address that Islam condemns violence and that Muslims, like others in the United States, want the terrorists to be punished.

Ingrid Mattson, vice president of the Islamic Society of North America, talks during a news conference with Sayyid M. Syeed, secretary general of the Islamic Society. The opening session of the largest annual convention of American Muslims was Friday in Washington.

“We’re for justice,” said Abdullah, a St. Louis imam, standing on a stage flanked by U.S. flags. “This is our country. American Muslims, we care for the betterment of this country and for every human being.”

Khadija Abdullah of Los Angeles read a prayer she wrote for those who died in the suicide strikes, thanking God for the efforts of the rescue workers and for the “comfort and courage” victims gave their families in their final phone calls. She also urged Muslims to “answer scapegoating and hatred” with love.

The impact of the attacks is a central theme of the conference, the most important U.S. Muslim meeting this year. Up to 30,000 people are expected to attend the four-day event, which is run by the Islamic Society.

It is the first time the convention in its 39th year is being held in the nation’s capital and comes as Muslims seek a greater public voice in what for many is their adopted country.

They have taken pains since the suicide hijackings to proclaim their loyalty to the United States, even as critics including the Rev. Franklin Graham, son of evangelist Billy Graham condemned the religion as evil.

The Council on American-Islamic Relations, a Washington-based advocacy group, has received 2,000 reports of harassment of Muslims since Sept. 11.

The opening prayer of the meeting was a verse from the Quran that urges Muslims to “stand firm for Allah” and “let not the hatred of others … make you deviate from justice.”

The conference will touch on many facets of Muslim life, including health care, parenting, charter schools and investing. Muslim law restricts how much profit may be made on investments.

Marriage also will be on the agenda. Families seeking spouses for their children will have the chance to meet face-to-face through a marriage service connected to the Islamic Society.

The National Coalition to Protect Political Freedom, a coalition of groups including the National Lawyers Guild and the American Muslim Council, scheduled a rally starting at noon Sunday at Freedom Plaza.

The event will end with a discussion of political strategy for Muslims in upcoming elections. Muslim organizations made their first collective endorsement of a presidential candidate in the 2000 race, when they backed George W. Bush.

There are no exact statistics for the number of Muslims in the United States. Estimates vary from 2 million to 6 million.

The Islamic Society of North America, based in Plainfield, Ind., is an association of Muslim organizations working in education, social service and other areas.