Updated at 2:15 p.m. ET
JERUSALEM - Israel's navy boarded two small protest boats trying to break the blockade of the Gaza Strip on Friday and towed them to an Israeli port just north of the Palestinian territory, officials said. The military said no one was hurt.
Troops boarded the boats without incident after repeated calls for them to turn around were ignored, the military said.
Pro-Palestinian activists have mounted numerous attempts to reach the impoverished coastal strip by boat to draw attention to the 5-year-old blockade, which they say amounts to the collective punishment of Gaza's residents. Israel says its naval blockade is vital in preventing weapons from reaching violent groups like Hamas, the Iranian-backed militant group that rules the Gaza Strip.
Once the two small vessels reach the port of Ashdod, the activists will be detained and asked to leave the country voluntarily from the airport near Tel Aviv. If they refuse, they can have access to a lawyer to appeal being sent home.
There were 27 activists from nine countries including the U.S. and Ireland aboard the boats from a group called Freedom Waves to Gaza.
In Gaza, activist Amjad Shawwa, called for the release of the activists, who he said "were on a civil trip to Gaza to help the Palestinians."
Israel sees the attempts to break the sea blockade as provocations and publicity stunts. It says the amount of aid in the small boats used by activists is insignificant, as Israel transfers 6,000 tons of aid to Gaza daily.
Shawwa said he had spoken with activists on the boats about an hour before they were boarded, when they were surrounded by Israeli naval vessels, but contact was later severed when the activists' satellite phones stopped working. It was not clear if Israel was jamming them.
The Israeli military issued a short video clip showing a naval official calling on the ships to turn around. "The Gaza area and coastal region are closed to maritime traffic as part of a blockade imposed for security purposes," the unidentified officer said.
"Your attempt to enter the Gaza Strip by sea is a violation of international law. We remind you that humanitarian supplies can be delivered to the Gaza Strip by land, and you are welcome to enter Ashdod port and deliver supplies through land crossings."
When asked what the boats were carrying, an activist replies "we have no cargo."
A statement from the activists later said the boats were carrying medicine and supplies for Gaza.
"Despite this Israeli aggression, we will keep coming, wave after wave, by air, sea, and land, to challenge Israel's illegal policies toward Gaza and all of Palestine," activist Huwaida Arraf said in the statement.
Israel's navy has intercepted similar protest ships in the past.
Last year, Israeli troops killed nine Turkish pro-Palestinian activists when they resisted an Israeli operation to halt a similar flotilla. Israel has said its troops fired live ammunition only after they were attacked by activists armed with knives, clubs and metal bars and they felt their lives were in danger. The activists say they were attacked first.
The incident sparked an international outcry and forced Israel to ease its land blockade on Gaza, which was imposed in 2006 and tightened, with Egyptian cooperation, after Hamas seized control of the territory in bloody street battles from the moderate Palestinian Fatah party the following year.
"The naval blockade has been recognized as legal and legitimate by the United Nations," said Israeli Foreign Ministry spokesman Yigal Palmor. "It's necessity has been stressed recently by the intensified rocket attacks from Gaza."
Militants in Gaza have fired thousands of rockets into Israel in the past decade, including a barrage last Saturday that killed one Israeli and injured several others.
Speaking after prayers at a Gaza City mosque, Ismail Haniyeh, the Hamas prime minister, addressed the passengers aboard the boats, saying, "Your message has been delivered whether you make it or not."
"The siege is unjust and must end," Haniyeh said.
On Thursday, the Obama administration warned U.S. citizens on the boats that they may face legal action for violating Israeli and American law. The U.S., like Israel and the European Union, considers Hamas a terrorist organization.
"We did not want to see this flotilla happen," State Department spokeswoman Victoria Nuland told reporters in Washington on Friday.