Israeli commandos Monday stormed a flotilla sailing to the Gaza Strip carrying pro-Palestinian activists and tons of humanitarian aid, organizers of the voyage said.
"The commandos descended on the ship from a helicopter," Audrey Bomse, spokeswoman for the Free Gaza Organization, told the German Press Agency dpa.
Unconfirmed reports said there were casualties on board one of the ships.
The so-called "Freedom Flotilla" had set out from Cypriot waters Sunday, on the last stage of what the organizers said they hoped would be a successful attempt to break Israel's siege of the Gaza Strip.
Israel vowed to prevent the ships from reaching Gaza, which is governed by the Islamist Hamas organization.