Protest boats leave Cyprus for Gaza

"Trying to breach the wall of silence surrounding Gaza is the best way to show that when is a problem is hidden, it doesn't exist," said Greek MP Tasos Kourakis who joined the activists.

Israeli officials said the delivery is illegal because Gaza is controlled by Hamas, which it considers a terrorist group. But they have refused to say how Israel would respond if the activists tried to break the blockade.

Free Gaza organizer Paul Larudee said it's "highly unlikely" the Israeli navy would fire on the boats to stop them. But he said the group expects Israeli authorities to intercept the boats and arrest those onboard.

Larudee said the group would contest any arrests in court on the premise that Israeli authorities committed kidnapping.