BETHLEHEM, West Bank — Israel prevented a gathering of foreigners here on Friday by blocking, deterring or deporting hundreds of air travelers who had been invited by Palestinian activists to fly into Israel’s Ben-Gurion International Airport and then travel to the West Bank for a week of “fellowship and actions.”

Israel has traditionally been welcoming of foreign tourists, including more than a million Christian pilgrims who visited this Palestinian city of the Nativity last year. But the Israeli authorities prepared for days to head off Friday’s planned fly-in. The Israeli news media added to the hype by calling it a “flightilla” — a reference to the flotilla of boats that was supposed to challenge Israel’s naval blockade of Gaza last month but has been stymied by Israeli pressure and by the cooperation of the Greek port authorities.

As a result, most of the foreigners who planned to fly to Tel Aviv and join the “Welcome to Palestine” initiative were either deterred from trying to come or were prevented from boarding flights to Israel by foreign airlines, on instructions from the Israelis.

The Palestinian hosts decried the Israeli measures, but also chalked up a small victory.

Fadi Kattan, a Palestinian organizer, said at a news conference in Bethlehem that he was “pleased — sadly pleased” that the episode had exposed what he described as Israel’s draconian anti-Palestinian policies.

Over the past few days, hundreds of police officers were deployed in and around the airport near Tel Aviv. Prime Minister Benjamin Netanyahu toured the base of operations at Ben-Gurion with his internal security minister, the police chief, security branch representatives and immigration officials.

There were persistent reports that the foreign visitors would try to create chaos and paralyze the airport, despite strenuous denials from the organizers of the campaign, who advocate nonviolence. They insisted that the foreigners wanted only to transit the airport and “go to Palestine.” (The West Bank has no airport of its own.)

By Thursday, the Interior Ministry had sent letters to foreign airlines with a list of 342 passengers it described as “pro-Palestinian radicals” planning to “arrive on commercial flights from abroad to disrupt the order and confront security forces at friction points.” Israel said people on the list would be refused entry, and it asked the airlines not to allow them to board flights, warning that if the listed passengers arrived at Ben-Gurion, they would be sent back on the same aircraft. Several airlines, including Lufthansa, complied with Israel’s request.

Several passengers at Charles de Gaulle Airport near Paris were barred from boarding a Lufthansa flight to Tel Aviv on Friday morning, and staged a protest. About 50 people were turned away, according to Agence France-Presse. There were reports of a similar disturbance at the Geneva airport.

“Like any other airline operating internationally, Lufthansa has to comply with the immigration laws and administrative decrees of the country we are flying to,” said Martin Riecken, a spokesman for the airline.

Such requests by national governments are not altogether uncommon, Mr. Riecken said, noting for example the United States’ no-fly list, which includes several thousand names.

Malev, the Hungarian airline, denied boarding to about 10 ticket holders in Paris on Friday. The decision to deny passengers the right to board does not indicate that “the airline likes or doesn’t like anyone,” said Marta Rona, a spokeswoman for the airline. Rather, she said, Israel had made it clear that the return of blacklisted passengers would be the responsibility of the airline.

“It’s our cost; it’s our responsibility; it’s our problem,” Ms. Rona said.

Yigal Palmor, the spokesman for Israel’s Foreign Ministry, said that the Israeli authorities had followed the activists’ plans and compiled the list of undesirables by tracking the Web sites and social networking of the organizations involved.

“We did not need the Mossad,” Mr. Palmor said, referring to Israel’s intelligence agency. “It was all out there in the open.”

At Ben-Gurion Airport, two American women were deported from Israel early Friday after flying in from Athens. In the afternoon, six Israeli left-wing demonstrators were detained for questioning after shouting pro-Palestinian slogans in the arrivals hall.

By early Saturday, 124 foreigners had been refused entry and were awaiting deportation, a spokeswoman for the Interior Ministry, Sabine Haddad, said. They had come in on six different flights and included Spanish, French, American, Belgian, Bulgarian and Dutch nationals, she said.

Israel’s Internal Security minister, Yitzhak Aharonovitch, had branded the potential visitors as “hooligans.” Mr. Netanyahu said that every country has the right to block the entry of “provocateurs.”

Still, Israeli commentators and some politicians have described the Israeli preparations as excessive and bordering on hysterical.

“The state of Israel has taken leave of its senses,” wrote columnist Eitan Haber on the front page of the popular Yediot Aharonot newspaper on Thursday. “Instead of welcoming these loony visitors, permitting them to sing, whistle and even raise signs, the world is liable to see the ‘Zionist storm troopers’ in action once again.”

Brigitte Von Winterfeld, 71, from Germany, was one of a few foreigners who got to Bethlehem to join the campaign. She said she flew in on Tuesday, chose a “smiley” immigration officer at the passport control booths, and told him she was coming to visit friends. Ms. Von Winterfeld said she spent a while here last year with the Ecumenical Accompaniment Programme in Palestine and Israel, a World Council of Churches organization that says it brings people from other countries to the West Bank to experience life under occupation.

The Palestinian organizers of the week’s program include well-known advocates of nonviolent protest like Sami Awad of the Bethlehem-based Holy Land Trust, and Mazin Qumsiyeh, a science professor at Bethlehem University. They said they were going ahead with the schedule as planned.

The itinerary includes visits to families in Palestinian refugee camps as well as demonstrations at various traditional Israeli-Palestinian flashpoints.