The Israeli navy boarded another aid ship bound for Gaza on Saturday, as Washington condemned as 'unsustainable' a blockade which Israel enforced earlier in the week by killing 9 people aboard a Turkish vessel.

Irish and other activists aboard the Rachel Corrie had ignored Israeli orders to divert to Israel's Ashdod port.

'The ship has been boarded and there was full compliance from the crew and passengers on board,' an Israeli military spokeswoman said.

The stand-off in the Mediterranean came as Washington, Israel's key ally, said its blockade of the Hamas-run Gaza Strip was 'unsustainable and must be changed' - the clearest sign yet of a shake-up in the embargo that has blighted the lives of 1.5 million Palestinians for the past four years.

Turkey, once Israel's main Muslim ally, has kept up its fury over the deaths of nine Turkish nationals in the raid on Monday. Prime Minister Tayyip Erdogan harangued Israel on Friday about ignoring the Biblical commandment 'Thou shalt not kill.'

Autopsy results, as reported by a British newspaper, found 30 bullets in the activists who died. Among the victims was a Turk with US citizenship.

Speaking ahead of the boarding, a spokeswoman for the Free Gaza campaign group, whose contact with the crew was patchy, said warships had been sighted by the freighter around dawn, before 6 a.m. (0300 GMT).

The ship is named after pro-Palestinian protester Rachel Corrie, who was killed by an Israeli army bulldozer in 2003.

Israeli government spokesman Mark Regev said the activists' motive was political and not humanitarian and they had rejected a joint Israeli-Irish proposal to resolve the standoff involving the Irish-owned merchant vessel.

'Late Friday, the activists on the boat rejected outright understandings reached between the governments of Israel and Ireland that will allow for the delivery of all humanitarian cargo for the people of Gaza. In so doing they clearly demonstrated that their goal is not supporting the people of Gaza but to make a political statement in support of the Hamas regime,' spokesman Mark Regev said.

Israel says its blockade of the Gaza Strip, tightened after Islamist Hamas seized the enclave from Palestinian President Mahmoud Abbas's Fatah faction in 2007, aims to keep out arms.

Washington had urged the Gaza aid vessel to divert to an Israeli port to reduce the risk of violence, but also stated its belief that the controversial blockade could not last in its current form.

'We are working urgently with Israel, the Palestinian Authority, and other international partners to develop new procedures for delivering more goods and assistance to Gaza,' a spokesman for the White House National Security Council said.

'The current arrangements are unsustainable and must be changed. For now, we call on all parties to join us in encouraging responsible decisions by all sides to avoid any unnecessary confrontations,' he added in a statement.

Irish Foreign Minister Micheal Martin had said the crew of the Rachel Corrie had indicated they were ready to accept inspection of their cargo at sea, prior to docking in Gaza.-Reuters