Leaders of Muslim and Arab-American advocacy groups are braced for a backlash if U.S.-led military strikes in Afghanistan lead to a terrorist reprisal on American shores.

There already have been hundreds of reports of hate crimes against Muslims and other religious and ethnic groups following the Sept. 11 terrorist attacks on the World Trade Center and the Pentagon, numbers not seen since the Persian Gulf war, leaders of the advocacy groups say.

Verbal threats and property damage have been reported across the country, and at least four homicides are being investigated as possible hate crimes, according to law enforcement officials.

"I think it would be reasonable to expect there would be another backlash if something else happens," said Ziad Asali, president of the American Arab Anti-Discrimination Committee in Washington.

700 possible hate crimes

Ibrahim Hooper, spokesman for the Council on American-Islamic Relations, a Washington organization, said his group has collected reports of more than 700 possible hate crimes across the United States. Federal officials said they are investigating at least 120 incidents.

"There's really nothing I can compare it to," Hooper said. "During the Gulf War, there were isolated problems, and after the crash of Flight 800 [off the coast of New York in 1996], but nothing like this."

Laila Al Qatami, a spokeswoman for the American Arab Anti-Discrimination Committee agreed. She said her advocacy group also has collected hundreds of reports, turning many over to the Justice Department.

The organization compiles lists of incidents for publication about every two years, and Al Qatami said the committee has collected more reports since Sept. 11 than it has recorded in any of its previous books. Its book for 2000 chronicled more than 200 incidents, for example, and the group has collected more than 300 reports since last month's attacks.

"The incidents have ranged from hate mail to verbal assault to crimes that have resulted in deaths," she said. "It's an unbelievable situation. The number of calls we're getting is unprecedented."

Officials said Muslims, Sikhs and those of Middle Eastern, and Central and South Asian descent have been targeted most often.

The latest killing being investigated as a possible hate crime took place Sept. 29 in Reedley, Calif. Fresno County Sheriff's police said Abdo Ali Ahmed, a 51-year-old convenience store owner, was shot to death, and investigators are seeking four teenage suspects. The FBI also is investigating, police said.

Imam Alaeddin Elbakri of the Badr Islamic Center in Fresno spoke at funeral services for Ahmed.

Before the shooting, Elbakri said, the most serious incidents he had heard of in the area involved some local cashiers refusing to serve Muslim women in stores. The killing has increased tensions significantly, he said.

Ahmed, the father of eight children, migrated to the U.S. more than 30 years ago, Elbakri said. He had worked his way up to owning his own convenience store.

He had received threats the week he was shot, including a hostile note left on his car, Elbakri and police say.

3 killings on Sept. 15

Three shootings that occurred Sept. 15 also are being investigated as possible hate crimes.

In San Gabriel, Calif., an Egyptian was gunned down in his import shop. The Los Angeles County Sheriff's Department said the murder of 48-year-old Adel Karas also is under investigation by the FBI.