Israeli commandos peacefully seized a ship that was attempting to deliver aid to Gaza Saturday, defiantly upholding the country's controversial three-year-old blockade of the Hamas-ruled territory.

The Israeli military said its members boarded the 1,200-ton Rachel Corrie cargo ship by boat, instead of rappelling onto it from helicopters.

Those who organized the trip said they plan to send three more ships toward Gaza, loaded with supplies, in the months ahead. They added that four captains have already volunteered their services.

"What Israel needs to understand is that nothing is accomplished with force," said Greta Berlin, who is with the Cyprus-based Free Gaza group.

Earlier this week, Israeli commandos clashed with passengers of a Turkish vessel trying to break the blockade, killing nine activists.

The deaths set off a wave of international criticism of Israel's blockade of Gaza, which activists say is illegal under international law and has pushed the area's 1.5 million residents into more acute poverty.

Israeli Prime Minister Benjamin Netanyahu issued a statement on the matter saying: "Forces used the same procedures for Monday's flotilla and Saturday's sailing but (were) met by a different response."

"On today's ship and in five of the six vessels in the previous flotilla, (their boarding) procedure ended without casualties. The only difference was with one ship where extremist Islamic activists, supporters of terrorism, waited for our troops on the deck with axes and knives."

Army spokesperson Lt. Col. Avital Leibovich said Saturday morning's takeover of the Rachel Corrie only took several minutes, and the ship was being brought to Israeli's Ashdod port.

The cargo will be inspected and any permitted goods will be sent through to Gaza, said Israeli Foreign Ministry spokesperson Yigal Palmor.

However, Hamas has announced it will refuse any aid from Israeli-intercepted vessels so long as the blockade is in place.

Footage provided by the Israeli military showed three navy vessels pulling up to the ship, while other clips showed activists sitting in the middle of the top deck.

CTV's London Bureau Chief Tom Kennedy said the ship stopped by compliance, not by force.

"The people on board finally obeyed warnings from the Israelis," Kennedy told CTV News Channel in a telephone interview from Jerusalem. "It was all done very peacefully."

The Irish ship is named after the American college student who was crushed to death by a bulldozer while protesting Israel's demolition of Gaza homes in 2003.

The ship was carrying about 1,000 tons of aid, including wheelchairs, medical supplies and cement.

Nobel Laureate Mairead Corrigan Maguire was on board the Rachel Corrie, as well as 10 other passengers and 11 crew members.

The passengers are mostly affiliated with the Free Gaza organization.

The organization said in a press release that the vessel was followed by Israeli ships for about two hours before the raid, and that their equipment was jammed by the Israeli navy.

Free Gaza spokesperson Greta Berlin said Saturday's takeover was "another outrage to add to the nine murdered" in last Monday's deadly raid.

Berlin vowed that the organization will continue to send ships to Gaza, saying four captains have so far volunteered their services.

Israel says the blockade must continue to keep weapons from being smuggled into Gaza from Iran.

"Israel will continue to exercise its right to self defence. We will not allow the establishment of an Iranian port in Gaza," Netanyahu's statement added.

With files from The Associated Press