BEN GURION AIRPORT, Israel - Hundreds of Israeli police, many undercover, were at Ben Gurion airport on Sunday to block the arrival of activists taking part in a "Welcome to Palestine" fly-in, police said.
"We have stationed several hundred police in order to maintain order at the airport," police spokesman Micky Rosenfeld told AFP.
According to Israeli public radio, at least 650 uncover police were deployed in and around the airport with orders to "exercise restraint, but to intercept any troublemakers."
Organisers of the so-called "flytilla" campaign, which is in its third year, had been expecting to welcome up to 1,500 people, more than a third of them from France.
But Israel has vowed to prevent their entry, and after warning foreign airlines they would be forced to foot the bill for the activists' immediate return, at least four European carriers cancelled tickets for a number of passengers heading to Tel Aviv.
Since Friday, French carrier Air France, Britain's budget carrier Jet2.com, Germany's Lufthasna and Swiss Air have all prevented an unspecified number of passengers from flying to Tel Aviv, European officials said.
But organisers of the "Welcome to Palestine" campaign on Sunday said many more had successfully managed to board flights heading for Israel, where on arrival, they were expected to openly declare their intention to visit the West Bank.
"A lot of people did manage to board planes and a lot of people have been denied," campaign organiser Mazin Qumsiyeh said, without giving numbers.
He said they were aware of four carriers which had blocked passengers from travelling - Lufthansa, Air France, Jet2.com and Brussels Air. He did not mention Swiss Air.
"We are expecting 1,500 people from at least 15 countries," he said, indicating most of them were expected to fly from Europe.
By Sunday morning, police said four passengers had been "detained for questioning" after disembarking from an El Al flight from Paris, with Rosenfeld saying they were likely to be deported.
The campaign's organisers say they want to publicise Israel's control of movement into and out of the occupied Palestinian territories and to demonstrate solidarity with the Palestinian people.
The term "flytilla" recalls earlier attempts by pro-Palestinian activists to reach the Israeli-blockaded Gaza Strip by boat, which have come to be known as "Freedom Flotillas."