Washington ( CNN ) -- The U.S. State Department on Friday ramped up its warnings urging Americans not to join other activists in a flotilla , expected to sail soon , aimed at challenging Israel 's maritime blockage of the Gaza strip . According to organizers , the flotilla is meant to commemorate the one-year anniversary of a similar flotilla that resulted in a clash in international waters with Israeli navy commandos that left nine people -- including an American citizen -- dead . Secretary of State Hillary Clinton told reporters Friday that she did n't think the plan `` is useful or productive or helpful to the people of Gaza . '' `` We have certainly encouraged that American citizens not participate in the flotilla , '' she said , `` and we are urging that all precautions be taken to avoid any kind of confrontation . '' Clinton 's comments followed an even harsher statement by State Department spokesperson Victoria Nuland , in which she criticized what she called `` irresponsible and provocative actions that risk the safety of their passengers . '' Last May , the Mavi Marmara -- owned by the Turkish Humanitarian Relief Foundation , or IHH -- and five other ships were on their way to Gaza , carrying humanitarian aid and about 700 activists from various countries , when Israeli soldiers swarmed aboard it . Despite international condemnation , an independent Israeli commission , led by retired judge Yaakov Turkel , later found that Israeli commandos `` acted professionally and in a measured manner in the face of unanticipated violence '' when they seized the Gaza-bound aid ship . In September , the U.N. Human Rights Council found Israeli forces `` committed serious violations of international law '' in the raid and suggested that six of the civilian deaths were `` consistent with ... an arbitrary and summary execution . '' Israel called the report `` as biased and as one-sided as the body that has produced it . '' The U.S. State Department earlier this week issued a travel warning advisting U.S. citizens `` against traveling to Gaza by any means , including via sea . '' `` Previous attempts to enter Gaza by sea have been stopped by Israeli naval vessels and resulted in the injury , death , arrest , and deportation of U.S. citizens , '' the State Department statement said . `` U.S. citizens participating in any effort to reach Gaza by sea should understand that they may face arrest , prosecution , and deportation by the government of Israel . '' Ali Abunimah , a blogger for the Electronic Intifada and supporter of the protest , accused Clinton of seeming to `` lay the ground -- indeed almost provide a green light -- for an Israeli military attack on the upcoming Gaza Freedom Flotilla . '' Activists say the blockade is illegal and has worked to undermine Gaza 's already fledgling economy . Israel has promised to block any attempt to break a blockade that they say is important in keeping weapons from being delivered to Gaza . The protesters said they raised funds to purchase a U.S.-flagged vessel , which they named `` The Audacity of Hope , '' a reference to the best-selling book of the same title by President Barack Obama . The boat , they claim , will carry 36 passengers , four crew members , and ten journalists . The protesters say they want to `` challenge U.S. foreign policy '' by providing aid and supplies directly to the citizens of Gaza , in spite of Israel 's blockade . `` We encourage all Americans to support our voyage , and to agitate with the US government and public opinion to ensure our safe passage to Gaza , '' wrote Robert Naiman , policy director at the advocacy group Just Foreign Policy , who said he 'll be part of the flotilla . The State Department counters that , if the activists want to help the citizens of Gaza , there is a better -- and legal -- way to do it . Victoria Nuland , the department 's spokeswoman , told reporters , `` We 've got to use the channels that are safe , the channels that are going to guarantee that the aid get where it needs to go to the people it 's intended for . '' Clinton added Thursday that it would be unwise to move toward Israeli waters and create `` a situation in which the Israelis have the right to defend themselves . '' But these words did not impress Abunimah , who wrote that `` in light of Clinton 's statements , if any blood is spilled it will not only be on Israeli , but also American hands . ''
50 activists plan to sail to Gaza to protest Israel 's blockage of the Palestinian territories . Last ##ly , 9 were killed after Israeli forces confronted a similar flotilla . Sec . of Hillary Clinton calls the group not ` ` useful , '' urging Americans not to take action . An activist say the group is giving Israel the ` ` green light '' to attack the flotilla .