WASHINGTON - Trying to stave off an anti-Arab backlash, President Bush visited the Islamic Center here yesterday, saying Muslims should be treated with respect because "the face of terror is not the true faith of Islam."

After an hourlong meeting with Muslim community leaders, Bush said last week's murderous acts by Islamic terrorists "violate the fundamental tenets of the Islamic faith."

In keeping with custom, Bush removed his shoes before entering the mosque.

Bush's remarks came in the aftermath of several weekend killings that are being investigated as possible hate crimes against those of Middle Eastern origin, as well as hundreds of reports of anti-Muslim and anti-Arab harassment and discrimination.

"Islam is peace," Bush said at the center, which is near the vice president's residence and in the heart of the embassy district. "These terrorists don't represent peace. They represent evil and war."

Speaking to reporters, Bush said Americans who are intimidating fellow citizens represent the "worst of humankind."

He said the Muslim leaders with whom he met share his outrage and sadness. "They love America just as much as I do."

Bush's remarks from the main prayer room of the mosque were broadcast live to the entire Arab-speaking world, from Morocco to the Iranian border, said a spokesman for Voice of America.

Outside the Islamic Center, where Washington's Muslims come to pray up to five times a day, many said they were feeling insecure in the wake of the attack on the nation and grateful the president had come to deliver a message of support.

"We all feel terrible about what has happened - and bad about what's happening now to us," said Tariq Syed, a law student whose family is from India. "The politicians are doing a good job of explaining that the terrorism was the act of a few people and does not represent our religion."

Syed said he's noticed suspicious glances, directed especially at Muslim women who wear scarves to cover their head, and heard mutterings. For his part, he decided against wearing an Arabic outfit to a wedding he attended in a small town in Pennsylvania over the weekend in favor of a suit.

"I thought it might be in my interest," he said.

Since last week's attack, the FBI has opened 40 hate crime inquiries nationally. FBI Director Robert S. Mueller said yesterday that agents were investigating two killings, as well as assaults, arsons and threats that may have been ethnically motivated.

Mueller would not disclose details, but James Zogby, president of the Arab-American Institute said he knew of three murders that had taken place over the weekend that are suspected of being hate crimes: the killing of a Sikh gas station owner in Mesa, Ariz., a Pakistani grocer in Dallas and an Egyptian in San Gabriel, Calif.

Many of the suspected retaliatory hate crimes have been directed at Muslim centers of worship and Muslim community centers, said Mueller, warning that civil rights violations would be vigorously investigated.

"I'll make it very clear - vigilante attacks and threats against Arab-Americans will not be tolerated," he said.

The Council on American-Islamic Relations said it had received several hundred reports of anti-Muslim harassment, threats, discrimination and violence in the past week and called on law enforcement agencies to step up protection of Muslim institutions and businesses.

The council accused the FBI and local law enforcement officials of questioning people of Middle Eastern origin based on appearance or name.

The practice of "racial profiling" was the subject of volatile debate in this country before last week. Nihad Awad, executive director of the council, said he fears that innocent people who had nothing to do with last week's attacks are being intimidated and harassed.