The U.N. Security Council called Tuesday for an impartial investigation into the Israeli attack against a flotilla carrying humanitarian aid to Gaza, and the immediate release of all civilians.

The statement by the council president condemned “those acts which resulted in the loss of at least 10 civilians and many wounded” and requested the immediate release of all ships and civilians held by Israel.

“The Security Council took note of the statement of the U.N. Secretary General on the need to have a full investigation into the matter and it calls for a prompt, impartial, credible and transparent investigation conforming to international standards,” the statement said.

The news came as an Israeli defense official said it would continue to prevent aid ships from reaching Gaza, despite the bloody end to a dawn raid Monday that saw at least nine people killed.

“We will not let any ships reach Gaza and supply what has become a terrorist base threatening the heart of Israel,” deputy defense minister Matan Vilnai told public radio.

Vilnai’s remarks were made as organizers of the so-called Freedom Flotilla said they were preparing to send two more aid boats to Gaza.

Greta Berlin of the Free Gaza Movement told AFP the next attempt to run the blockade would not take place for several days.

“The Rachel Corrie (cargo ship) is currently located off the coast of Italy and the other boat is still being repaired,” she said.

The first six ships that left Cyprus on Sunday — carrying more than 700 passengers — were on a mission to deliver about 11,000 tons (10,000 tonnes) of supplies to Gaza, which has been under a crippling Israeli blockade since 2007.

CNN has reported one American was injured and up to nine U.S. citizens were also thought to have been on the flotilla. A Briton and an Australian man were also among those wounded during the raid, AFP reported.

Israel detained 480 pro-Palestinian activists captured during the commando raid and will expel 48 others, according to a public radio report cited by AFP.

Those detained were being held at the southern Israeli prison of Ashdod, while the other 48 were being taken to Ben Gurion international airport to be sent back to their home countries, said the report.