Organizers of an international flotilla are accusing Israel of sabotaging a second ship that they planned to include in a mission to break an Israeli naval blockade of the Gaza Strip.

The organizers said Thursday they had discovered damage to the engine of the Irish boat Saoirse in the Turkish port of Gocek, where it had been berthed for the past few weeks.

They called the damage an act of sabotage committed by professional divers and blamed it on Israel, which has warned it will not allow the flotilla to breach the Gaza blockade.

An Israeli foreign ministry official ridiculed the allegations, telling a Swedish news agency that they sound like a plot from a James Bond movie.

The organizers said the Irish boat could have sunk, resulting in fatalities, if it had gone to sea with a damaged engine. On Monday, they reported similar damage to the Swedish ship Juliano at the Greek port of Piraeus and also blamed it on Israeli sabotage.

Israeli Defense Minister Ehud Barak says if the ships insist on challenging the Gaza blockade, they will be intercepted by the Israeli Navy and the organizers will be responsible for any injuries or damage.

Israeli officials say they hope to avoid a repeat of its botched raid on a Gaza-bound flotilla last year, when nine pro-Palestinian activists were killed in a confrontation with Israeli commandos who boarded a Turkish ship.

Israel says the naval blockade is necessary to prevent weapons from reaching the Palestinian militant group Hamas that rules Gaza.

Organizers say they hope to sail to Gaza with about 10 boats and two cargo ships loaded with humanitarian aid for the Palestinians.

Most of the ships are docked in Greece, where some have encountered administrative problems, also blamed on Israel. About 300 people plan to join the convoy, including journalists, politicians, writers and religious figures.

Israel, the United States and the United Nations have urged the flotilla to sail to Israeli or Egyptian ports and transfer its cargo legally to Gaza over land.