JERUSALEM — Organizers of the Gaza-bound flotilla accused Israel of sabotaging a second ship, though they have no proof.

The engine of the Irish-flagged ship Saoirse was seriously damaged Wednesday while docked in Turkey’s territorial waters, reported Haaretz’s Amira Hass, who is scheduled to travel with the flotilla. Other reports said the ship’s propeller was damaged.

The Saoirse has dropped out of the flotilla, according to the Irish Times.

“I saw the damage and it is clear that it was done in a planned and professional way,” flotilla spokesman Dror Feiler told Army Radio. “The Israeli government is the only one that could benefit from this.”

Feiler admitted that he had no proof that Israel was responsible for the damage.

The Saoirse was the second ship to be damaged in what flotilla organizers believe are acts of deliberate sabotage.

On Monday, the propeller of the Juliano, on which Swedish, Norwegian and Greek activists are scheduled to travel, was discovered to be broken.

Security guards are now watching the remaining flotilla ships around the clock, according to reports.

The U.S.-flagged Audacity of Hope still has not been given permission to sail following a complaint that it is not seaworthy.

Only two flotilla ships in Greek ports have been given permission to sail, the French news agency AFP reported.

The flotilla’s departure date, originally scheduled for the middle of this week, will be pushed off by several days, according to reports.