MUHAMMAD ALI, the most prominent of America's seven million Muslims, pleaded with Americans yesterday not to condemn all his fellow worshippers for the attacks on New York and Washington.
His call came as jitters spread through the community about possible revenge attacks. "I am a Muslim. I am an American," said the former world heavyweight boxing champion.
He spoke after two days of what Muslim spiritual leaders yesterday were calling "aftershocks" that have shaken their communities in widely scattered parts of America: Detroit and Miami, Boston and San Francisco, New York and Los Angeles.
The hostility against mosques and turbaned taxi drivers, against women who habitually wear headscarves and long dresses as they walk their children to Muslim schools and nurseries, was a grim echo of the immediate reaction to the Oklahoma City bombing in 1995.
Then, as snap judgment blamed Muslim terrorists, mosques were defaced, families were harassed and Arab-American travellers were detained in airports. It soon emerged that the federal building in Oklahoma City had been blown up with a truck bomb made by members of a Right-wing militia group, all white Christians.
In Irving, in suburban Dallas, the plate-glass windows of a modern mosque were shattered and the building pock-marked with bullets after a drive-by shooting.
In Cobble Hill, Brooklyn, the Arab-American Family Service Centre took its name off the front door and its executive director, Emira Habiby-Browne, a Palestinian-American, said the door would remain bolted until the anti-Arab anger had subsided.
Detroit has the country's largest concentration of Arab immigrants; in suburban Dearborn one of nearly every three residents is Arab-American. The city has dozens of mosques, Islamic centres and Islamic schools. All are under police guard.
Similar precautions were in force in San Francisco, where one mosque found a bag of what appeared to be blood on its doorsteps.
In Miami and Fort Lauderdale, Islamic centres and mosques were vandalised or defaced with graffiti - "Kill all Arab terrorists", "Go back to your own country" - and in Alexandria, Virginia, where two bricks were thrown through the windows of an Islamic bookshop. Handwritten hate messages were found attached to the bricks.
In New York, police were guarding the biggest mosque in the city yesterday, fearful of reprisals in a city swaying between sorrow and the desire for revenge. The Islamic Cultural Centre on the Upper East Side of Manhattan is an impressive edifice, built 10 years ago with funding from the Middle East, including £12 million from Kuwait.
There is no indication either inside or outside the temple that anything unusual has happened in the last few days. It is perhaps the only religious building in New York that does not have a collection box for the bereaved. The police have been on guard since 4am Wednesday morning and say they have been told to "look out for violence".
Mike Clarke, a New Yorker, has been standing outside the mosque waving American flags since Tuesday evening, though he has been shunted on to an opposite corner, away from what police call a "heightened security area". Small gangs of supporters come and go, sometimes chanting in the direction of the mosque.
"I am an American and I should be allowed to fly the flag in America," said Mr Clarke. "I have been getting mostly support, especially from the firemen and police driving by and giving me the high-five."
Taxis hoot their approval and passers-by ask if they can buy one of his flags. The main entrance to the building is closed, though worshippers can enter through a side door.
Inside, Dr Mohammed Gemeaha, the imam, or priest, is polite if nervous. "We condemn the attack and think of those who have suffered," he said but did not elaborate. He has had no more than the usual number of visitors. Other Islamic religious buildings in Manhattan have, like much of the city, closed.
Muslim groups are seen as far more integrated into American society than they were in 1993, when the World Trade Centre was bombed for the first time. However, they have been warned to be on the look out for revenge attacks.
Muslim groups in Washington have urged mosques to take security measures and advised those who "wear Islamic attire" to avoid public areas.
Indian men and women find they are being mistaken for supporters of Osama bin Laden and report being accosted in the street, sometimes by police, they claim. Popular shopping areas for Muslims and Arabs are also lined with police, in particular Atlantic Avenue in Brooklyn.
Mosques in other parts of the country have closed their doors. Few Arab or Muslim businesses are taking phone calls, because they have received so many threats.
Police in New York have arrested two men after a Sikh who lives in Queens was beaten with a baseball bat. Others were shot at with a paint-ball gun.
Another mosque in Queens is being picketed by an elderly man with a makeshift placard, which reads simply: "Get out of our country."