An Irish ship has dropped out of the pro-Palestinian flotilla planning to break Israel's blockade of Gaza, citing sabotage, and a US ship declared it may set sail from a Greek port for Gaza without permission, activists said.
Up to 400 international activists had been due to sail this week to Gaza aboard 10 ships leaving from Greece to protest against the naval blockade that Israel imposed on the Palestinian territory after Hamas militants overran it in 2007.
An Israeli raid on a similar flotilla last year killed nine activists on a Turkish ship and each side blamed the other for the violence.
The Irish ship MV Saoirse on Thursday had to abandon plans to set sail because of what it called Israeli sabotage.
Activist Huwaida Arraf told Israel's Army Radio that the ship's engine was damaged while in port and could have lead to deaths on board.
The alleged sabotage occurred at the Turkish coastal town of Gocek where the MV Saoirse has been berthed for the past few weeks, organisers said.
Earlier this week, activists said Israeli agents damaged the propeller of a Swedish ship in the Greek port. Israel has refused requests for comment on the allegations.
On Thursday, American activist Ann Wright said Greek authorities were bowing to Israeli pressure and deliberately stalling the departure of 53 passengers and crew - including 11 journalists - aboard a ship named the Audacity of Hope from a port near Athens.
"We're fed up with it already, we've already waited seven days. We were ready to go a week ago," Ms Wright said. She would not say how long activists would wait for the all-clear before the 33-metre ferry begins its journey. But she said the Greek coast guard would "probably" stop the boat shortly after departing.