Israel on Sunday barred 43 pro-Palestinian activists who had flown in for a "Welcome to Palestine" campaign as hundreds more would-be protesters were stranded at airports across Europe.

As hundreds of police deployed at Israel´s main international airport in a bid to stop activists from entering, Europe´s main airlines faced a wave of passenger fury after cancelling some 300 tickets following heavy Israeli pressure.

By late afternoon, Israeli police said they had detained 43 passengers on suspicion of being part of the fly-in campaign, better known as the "flytilla," with all facing deportation.

Organisers of "Welcome to Palestine," now in its third year, had been expecting to welcome up to 1,500 people as part of a campaign to expose Israel´s control of movement both into and out of the occupied territories.

But only three activists managed to reach a news conference held by organisers in the West Bank town of Bethlehem in the early evening.

Israel had vowed to prevent the activists´ entry, warning airlines they would be forced to foot the bill for the activists´ immediate return home in a move which saw many carriers toeing the line. Scores of activists staged angry demonstrations at airports in several European capitals.

At Roissy-Charles de Gaulle airport outside Paris, protesters carrying banners, Palestinian flags closely monitored by CRS riot police, headed for the Lufthansa desk.

"Today, the checkpoint is in Paris!" the demonstrators shouted. Their banners read: "Roissy, Palestinian territory" and "Paris, following Israel´s orders!"

Lufthansa and Swiss Air both stopped nearly 90 passengers on an Israeli list of undesirable people take up their bookings on flights from Paris to Tel Aviv.

At Brussels airport, protests erupted after at least 100 French and Belgian nationals were unable to board flights with Brussels Airlines, Lufthansa and Swiss Air.

In Geneva, several dozen activists held an angry demonstration after around 45 people out of a group of 70 who had been planning to join the campaign were barred from boarding an easyJet flight.

At Istanbul airport, another 50 activists were stranded after Turkish Airlines reportedly refused to allow them on board, Anatolia news agency reported.

In Vienna, Austrian Airlines said five passengers were barred from flights to Tel Aviv, and in Rome, Alitalia turned back seven Italian activists, press reports said.

Air France and two British budget carriers, Jet2.com and easyJet, also barred an unspecified number of passengers, with easyJet confirming it had prevented activists from flying to Israel from London and Switzerland.

Despite the success of its diplomatic campaign to pressure European carriers not to allow activists to board flights for Tel Aviv, Israel deployed hundreds of police at its main international airport with orders to "exercise restraint, but to intercept any troublemakers."

Sunday´s arrests took place far from the whirring cameras with police detaining activists from France, Spain, Italy, Switzerland, Canada and Portugal.

Thirty-one of those detained had refused to board planes back to their homelands, police spokesman Micky Rosenfeld told AFP.

"Twelve have been sent back to the destinations from which they arrived, and the rest have been transferred to a prison in Ramle (near Tel Aviv)," he said, adding that most of them were French. In addition, Rosenfeld said, "nine Israelis were detained for being involved in public disturbances at the terminal."

At the Bethlehem news conference, one of the three activists who managed to attend slammed the Israeli internal security minister for saying the "Welcome to Palestine" campaign was provocation.

"We are not criminals," the activist said. "We should all be able to fight -- peacefully -- for what we believe in."

Last year, around 800 people tried to join the campaign, with many blocked from flying by airlines. Another 120 were denied entry by Israel and deported. (Copyright © 2012 Agence France Presse. 04/15/12)