"There are a lot of Muslims who were victims among those who died in the World Trade Center," said Imam Mohammad Gemeaha of The Islamic Cultural Center of New York, the city's largest mosque. "Many Muslims [are] dead, like Christians, Jews and all the others. Many Muslims in this congregation hurried to the Red Cross to save as much as they could by donating their own blood. I urged them to give their own blood and to participate in the evacuation effort."

Dr. Shaik Ubaid, spokesman for the New York chapter of the Islamic Medical Association, said at least 15 Muslim doctors are on staff at St. Vincents Hospital, the trauma center closest to the World Trade Center. He said the number is even higher at Bellevue Hospital, which also treated the injured.

"There are Muslims among the victims and there are Muslims among the heroes also," said Dr. Ubaid, 39, a neurologist at New York Presbyterian Hospital.

There has been a backlash by some Americans who paint all Muslims with a broad brush as evil. Some Arab-Americans have been subjected to harassment and shouts, mosques have received bomb threats and Muslim schools were closed because of safety concerns.

Khaled Kadry, 26, a graduate student at the City University of New York, said it's too dangerous to don his kufi – a small round hat identifying him as a Muslim.

"I live in a white neighborhood," he said. "You have to be more cautious because you don't know what people will do to you."

His friend Allura Gheit, 27, still wears a hejab, the traditional head and neck covering for Muslim women. But she said people on the streets give her harsh stares or roll their eyes.

"A man screamed at me on the street the other day," Mrs. Gheit said. "Another man asked why I would wear this, because there is so much violence. I don't know what could have happened."

Hafeez Rehmen, 39, a taxi driver from Brooklyn, said his wife, Rehana, gave blood twice last week, though the couple did not know any of the victims.

Wagdi Helmy, 40, a lawyer from Egypt who drives a cab in New York, said he didn't know any victims. However, four Egyptians were caught in the rubble.

"We don't agree [with terrorism]," Mr. Helmy said. "We like to live in peace. We're like everyone. Everyone who works here likes to be here because it's a type of freedom. You feel it's a second home. It's a first home for me. It's sad for everyone."

Dr. Ubaid did not return to his home on Long Island for several days last week because he was working. He said his 15-year-old daughter was upset when both her school and mosque were closed because of fear of reprisal. He said that when they talked, she told him: "I'm a victim twice. I'm a victim of the terrible terrorists and the victim of my own countrymen who don't understand me. We're not even being allowed to grieve, and we are suffering as much as they are."

Dr. Ubaid said he understands the initial flash of anger against Muslims, as long as it passes. In fact, he said, he sees progress of a sort because he thinks the backlash was worse after the 1993 World Trade Center bombing that killed six people.

"I do not hold a grudge," he said. "But this [terrorism] is not a religious problem. This is a crime and sociological problem. We need to get at the root causes."