The United States warned that a new effort by pro-Palestinian activists to send a flotilla to challenge Israel’s blockade of the Gaza Strip was “dangerous” and urged US citizens not to take part

The United States warned on Thursday that a new effort by pro-Palestinian activists to send a flotilla to challenge Israel's blockade of the Gaza Strip was “dangerous” and urged US citizens not to take part.

Activists set sail from Turkey on Wednesday aboard two yachts carrying medical supplies, they announced that they would reach Gaza within two days. The Israeli military said it would not permit them to “breach” its blockade.

In May 2010, nine Turkish activists, including one with dual US-Turkish nationality, were martyred in an Israeli raid on a similar convoy that nearly ruptured ties between Turkey and Israel.

State Department spokeswoman Victoria Nuland said Washington had been in touch with the Turkish government on Thursday about the flotilla, and had also spoken to Israeli officials.

"My sense of this was that, given the way this came together there was some element of surprise for both the Turkish government and our own government," Nuland said.

She said the United States had sought clarification on news reports that Turkish warships might be accompanying the flotilla and were told "quite emphatically" by Turkey that this was not the case. "We've been clear to them that we think that would be an extremely bad idea and they've now reassured us that that is not what they are doing in this case," she said.

Nuland repeated US warnings about earlier flotilla plans, saying that US citizens who take part in efforts to deliver material support or other resources to Gazans could face civil and criminal penalties.

The 27 activists on board the Canadian and Irish vessels came from Australia, Canada, Ireland and the United States, and included Palestinians and at least one Israeli Arab citizen, according to organizers. Turkey has stressed that the vessels were not Turkish-flagged, had no Turkish passengers and the captains were not Turkish.

An Israeli military spokesman said on Thursday that the Navy is fully prepared for the arrival of the two-boat flotilla.