The Free Gaza movement announced yesterday that the admiral of the Israeli navy has warned the 47 passengers and crew aboard the SS Free Gaza and Liberty that they should not sail to the Gaza Strip because Israel is conducting naval exercises off Gaza and in nearby international waters.

Speaking to the media at quayside on behalf of the campaign, Paul Larudee, said that the boat people had been told that "all traffic has to stop" in the sea. But Larudee declared that this would not deter the activists' mission of breaking the siege and blockade of Gaza and its 1.5 million citizens.

He stated: "This is the first time in 41 years [since the 1967 occupation of Gaza] that any one has travelled in those waters" without Israel's permission. He added: "We are not delivering humanitarian aid. This is about the right of the Palestinians to live freely," to leave and return to Gaza and to choose what goods should leave and enter Gaza. "Nobody needs freedom now more than the Palestinians."

Larudee also asked if Israel planned to bomb the Liberty, a reconditioned Greek fishing vessel named after the USS Liberty, which was bombed and strafed by Israeli warplanes on June 8, 1967, in international waters off northern Sinai.

During this attack, 34 US seamen were killed and 172 were injured. The incident was covered up by then-President Lyndon Johnson, US Defence Secretary Robert McNamara and Admiral John S. McCain, father of the current Republican presidential candidate.

Jim Ennes, an officer on the USS Liberty, spoke to Larudee before the Free Gaza mission and said that survivors asked the activists to read a prayer when the boats enter international waters off Gaza.

During a dockside ceremony, Huwaida Arraf, a Palestinian peace activist, threw one long-stemmed rose into the harbour below the Liberty to commemorate the lives of 14 Gaza fishermen killed by Israeli military action over the past two years and the 37 US seamen who died on the USS Liberty. A message of good wishes from the family of Rachel Corrie, the US activist killed by an Israeli bulldozer in Gaza, was also read out.

Jeff Halper, an Israeli volunteer, said: "The Israeli foreign ministry called us pirates. Now we call ourselves peace pirates. It's only pirates who can bring hearing aids to deaf children in Gaza."

One of the few humanitarian items carried by the boats is a consignment of 200 hearing aids.

A Greek member of parliament, Tassos Kourakis of the Coalition of the Radical Left, will sail to Gaza on the mission. Kyriakos Triantafyllides, Cypriot member of the European Parliament and chairman of its delegation to the Palestinians, announced that the mission has the support of the delegation. He called on Israel to ensure that the boats' passage to Gaza is peaceful. The activists kept the exact time secret for security reasons.