JERUSALEM — Israel on Tuesday expelled seven foreign pro-Palestinian activists detained after flying into Israel for protests at the weekend, leaving five still in custody, an official said.

"There are three British people, an Irishman and a German," immigration service spokeswoman Sabine Hadad told AFP.

She was unable to say when they would be deported.

The detainees were part of the "Welcome to Palestine" campaign in which up to 800 people from Europe and the United States planned to fly to Israel and head to the Palestinian territories to visit Palestinian families.

Israel said it prevented hundreds of people from boarding at their ports of departure by notifying airlines of ticket-holders who would not be admitted to the country.

Of those who managed to arrive, 120 were denied entry and taken into custody, although a handful were later admitted after signing pledges not to take part in public disorder.

The "Welcome to Palestine" campaign -- dubbed "flytilla" -- took place as a flotilla of ships trying to break a blockade on the Gaza Strip was prevented from leaving Greece.