Draped in a floor-length black garment, her head covered in a white scarf, and with only her hands and face exposed, Majida Salem cuts an exotic figure even in ethnically diverse Los Angeles. When she emigrated from Jordan seven years ago, she was prepared to encounter stares from puzzled Americans.

Now, however, curiosity has evolved into hostility and "the looks are different," Salem said a few days before war erupted in the Persian Gulf. "At first they questioned my appearance," she explained in near-fluent English, "but they didn't have those hateful looks."

These are wrenching times for Salem and millions of other Muslims living in the United States. Through immigration, a high birth rate and conversion, especially among American blacks, Islam is one of the fastest-growing faiths in America. Yet Muslims say their beliefs are widely misconstrued as war-prone and hostile to Western ideals. Isolated in a culture that makes little effort to understand them, they fear their neighbors will hold them responsible for a war most say they did not want.

"When the bodies of American youth come back, (people) are going to blame the Muslims," predicted Zaheer Uddin, editor of a Muslim magazine in Jamaica, N.Y. "It will give a very negative picture (of us)."

War has come just as many Muslims have begun building bridges to mainstream America by, for example, participating in interfaith services and entering political life for the first time. Now some worry these fledgling efforts will be undermined.

No one knows exactly how many of the world's 1 billion Muslims live in the United States, although there is general agreement that by the year 2010 Islam will overtake Judaism, with its 5.5 million adherents, as this nation's second leading religion.

The very vagueness of the population estimates--anywhere from 3.5 million to 6 million--is powerful evidence of how little political organization Muslims have. As one sign of Islam's swelling presence, however, the number of mosques and student centers has grown from 598 to more than 950 in the last five years.

Two-thirds of the Muslims in this country live in 10 states, with more than 20% in New York and New Jersey, and 10% in California, according to Dawad Assad, secretary general of the Council of Masjid (Mosques) in the U.S.A., which represents 195 houses of worship. Active Muslim communities with a growing number of mosques are found in New York City, the greater Los Angeles area, Chicago, Boston, Houston, Detroit and the Washington area.