Israel blocks 'flytilla' activists
Dozens of pro-Palestinian activists trying to reach Israel have been blocked at airports in Europe or deported after arrival in Tel Aviv.
Israeli officials asked foreign airlines to stop black-listed travellers reaching the country.
Activists are planning to spend a week in the occupied West Bank.
Their so-called "flytilla" comes as the Greek authorities have blocked the sailing of an aid flotilla trying to break the Israeli blockade of Gaza.
Reports say two American women originally involved in the flotilla have already been deported from Ben Gurion Airport after flying in from Athens to try to join the latest demonstration.
The group, Welcome to Palestine, invited between 600 and 1,000 foreigners to visit locations such as Bethlehem and Ramallah starting on Saturday.
The activists planned to inform Israeli immigration of their intention to visit only Palestinian areas on arrival at the airport knowing that this could see their entry blocked.
Organisers said the purpose was to highlight Israel's control of Palestinian borders.
A number of activists were turned back at Paris's Roissy Charles de Gaulle airport as they tried to board a flight to Tel Aviv on the Hungarian airline Malev.
An airport spokesman told AFP news agency their reservations had been cancelled at the request of Israeli authorities who had issued a "list of undesirable persons".
In a statement on Friday Welcome to Palestine called moves to prevent activists from travelling to Israel as "provocative, blackmailing and illegal".
Israeli Prime Minister Benjamin Netanyahu has ordered authorities to "act with determination, while trying to avoid unnecessary friction" with anyone taking part in a provocation, a statement from his office said.
Security remains high at Ben Gurion Airport in Tel Aviv. Israeli police say they are determined to stop any disturbances.
Meanwhile, the Greek coast guard on Thursday intercepted the lone remaining boat from a 10-ship aid convoy that has been trying to sail to Gaza since the end of June.
The French boat - Dignite al-Karama - was detained for "administrative reasons" on a refuelling stop in Crete, organisers said.
Israeli officials have dismissed as "ridiculous" claims by the organisers that Israel has sabotaged two ships - one Irish and one Swedish - and pressured the Greek authorities to block the sailings of the French yacht, as well as US and Canadian vessels.
The Quartet of Middle East peace mediators - the UN, US, EU and Russia - has urged activists to avoid a potential confrontation with Israel, pointing to last year's deadly clashes on the Freedom Flotilla that left nine activists dead.
Israel increased sanctions on Gaza in 2006 after militants captured Israeli soldier Gilad Shalit. It tightened them further still a year later when Hamas ousted rival Palestinian organisation Fatah from the territory.
Although the Islamist group won Palestinian legislative elections in January 2006, it refuses to recognise Israel or to renounce violence and is designated in the West as a terror organisation.
Israel eased the restrictions last year in response to international pressure following the activists' deaths.