JERUSALEM -- -- Nawal Hamad of Fairfax City and her four children arrived at Ben-Gurion Airport on a Pan American flight from Paris late last month on a long-planned trip to the West Bank town of El Bireh to visit her parents.

The airport was as far as they got. After a verbal altercation with Israeli immigration authorities, she and the children were detained for 12 hours and denied the right to call the U.S. Consulate or speak to relatives waiting outside the terminal. They were put on the next Pan Am flight back to Paris.

The case of Hamad and her family is one of about 30 reported to U.S. officials in which American citizens of Palestinian ethnic origin have been denied entry to Israel this summer, according to Abdeen Jabara, president of the American-Arab Anti-Discrimination Committee, a Washington-based advocacy group. There also have been reports of black Americans being harassed by Israeli immigration officers.

The U.S. State Department has warned Israel that it will issue a travel advisory unless Israel changes its policy toward visiting black and Arab Americans, U.S. officials said yesterday in Washington. The advisory would inform these groups that they "might experience problems getting in," a U.S. official said.

Jabara, who is here collecting accounts of such cases, also says there have been about 50 reported cases of Palestinians being required to surrender their passports at the airport or to post bonds as high as $5,000 in an attempt to ensure that the visitors do not overstay their tourist visas.

"Arab Americans are being singled out on the basis of their names and nothing else," said Jabara in an interview. He said that Jewish Americans are given easy and unlimited access to Israel, in contrast to the treatment given Palestinian Americans seeking to visit relatives in the Israeli-occupied West Bank and Gaza Strip.

American diplomatic officials here confirmed that the United States has complained to Israel about allegations of mistreatment. "We've made clear to the Israelis that we are against anything that in our view discriminates on the basis of race, religion or national origin," said a spokesman for the U.S. consulate here.

He would not comment further, but a diplomatic source said the cases collected by the consulate showed "an ingrained pattern" of abuse that has worsened over the past two years. "We'd hoped we had gotten our point across last summer, but it now seems clear that we didn't," he said.

U.S. officials also have complained about the alleged harassment of black Americans, several of whom have been turned away at the airport as the Hamads were. In two cases, parties of black pilgrims were required to post bonds of at least $50,000 for the group because Israeli authorities feared that they were planning to join the Black Hebrews sect, a group of about 1,500 black Americans who entered Israel illegally beginning in the late 1960s and have stayed, despite efforts to deport them.

An Israeli Foreign Ministry official rejected such allegations of harassment. "We get the same complaints every summer," he said, contending that the restrictions were not aimed specifically at Arabs but applied to any foreign visitors whose purpose in coming here might be suspect.

"Immigration officers look at every case individually, and if they suspect people are coming under false pretenses -- for example, saying they are here as tourists when their aim is to stay -- they have the right to turn them away," said the official. "It's a procedure taken by every country in the world, including the United States."

But Hamad, who is a branch manager of the Central Fidelity Bank in Arlington, said her treatment by immigration officials when they arrived in Israel on the night of June 26 was anything but standard.

"I really felt they were trying to make things as difficult and unpleasant as possible," she recalled from Fairfax City in a telephone interview. "I just wanted to get out of there and see my family, and I was very angry."

She said she and her four children, ages 14 to 22, along with four other children accompanying them, were pulled out of line and made to sit for several hours outside a passport control office after she asked that their passports not be stamped because they planned to travel to a wedding in Amman, Jordan.

Like most Arab countries, Jordan does not allow entry to tourists who have visited Israel, and immigration officials here routinely accede to requests to withhold the stamp as a courtesy. Nonetheless, says Hamad, an immigration officer stamped two of the passports and then ordered the Hamads out of the line.

An official eventually examined their passports and informed the Hamads that they would not be allowed entry. Asked why, the official's only reply, Hamad said, was "because we don't want you here." When one daughter protested, she was told to "shut up," Hamad said.

The Israeli version differs at this point. The Israelis claim that Hamad and some of her children began making anti-Semitic remarks in Arabic, including comments about the Holocaust, and that this was the reason they were denied entry. One officer told an official that, had the incident not taken place on a Friday night, the Jewish Sabbath, he would have ordered Hamad's arrest for racist remarks, a criminal offense here. Hamad called the allegation "nonsense."

The family then was escorted upstairs to a detention area, where Hamad said her request to phone her relatives or the U.S. consulate was denied. She said the family was provided a loaf of stale bread and cold rice, but no drinks, and her request to change money so that they could use a soft drink machine also was denied.

Eventually the four children accompanying the Hamads were released, and she gave one a note for her family waiting outside the terminal. They in turn phoned the U.S. consulate, and an American diplomat, political officer Mark Kennon, drove to Ben-Gurion at 3 a.m. seeking to assist the family.

Kennon was unsuccessful. The Hamads were forced to board a Pan Am flight back to Paris at 6:45 a.m. and, according to Hamad, an Israeli Pan Am official accompanied them and insisted that they board a connecting flight to New York despite her objections.

Upon arriving in New York, she said, the family discovered that someone had dumped shampoo, peroxide and lotions from a toilet case into a separate suitcase holding dresses and other clothing.

Hamad said she wants to go back, but has gotten no firm response so far to complaints she made to the State Department and to Rep. Frank R. Wolf's (R-Va.) office.

The Israeli official said he could not provide details of the Hamad incident, but he branded the Arab-American Anti-Discrimination Committee's efforts to publicize her case and others as "a clear campaign to portray Israel in a negative light."