Sondos Ferwana, a spokeswoman for the International Coalition for the Fourth Freedom Flotilla, told Anadolu Agency on Wednesday evening that Israeli naval forces had “captured the ship”.
The Israeli military confirmed the ship’s seizure in a statement.
“The Israeli Defense Forces managed to quickly seize the ship without causing any injuries among passengers,” the statement said.
The military said the crew initially refused the navy’s orders to change course. “This forced us to intervene and seize the ship before it violated the legal maritime closure imposed on the Gaza Strip.”
According to reports on Israel’s Channel Two television station, the aid ship was intercepted -- without resistance -- some 80 kilometers (50 miles) off Gaza’s coast. The Jerusalem Post newspaper quoted military sources as saying the navy was preparing to tow the ship to Ashdod.
Ferwana described the incident as “another act of Israeli piracy” and said all contact with the ship -- which is carrying humanitarian aid and around a dozen female activists -- had been lost.
“We don’t know the fate of the activists aboard,” she told Anadolu Agency, adding that Israeli naval vessels had surrounded the ship to halt its progress to Gaza.
Half an hour before the boat lost contact, Anadolu Agency contacted Madeleine Habib, the ship’s captain. She said the women were in high spirits and were preparing oatmeal and boiled eggs.
She added that they expected to be detained for a few days and did not intend to accept food during Israeli detention.
In a pre-recorded video, Marama Davidson, a New Zealand lawmaker aboard the Zaytouna-Oliva, said: “We are peaceful women who stood by principles of peace and the Israeli oppression forces had no reason to kidnap us, to take us hostage. They could have just let us through to Gaza.
“They have chosen to oppress us women. We need the world to pressure the Israeli government for our immediate and safe release.”
In a statement, organizers Rumbo a Gaza said: “The Israeli armada has again acted with total impunity and against all international legality, assaulting a civil boat that was headed towards Gaza in the international waters of the Mediterranean Sea.”
Passengers on the Zaytouna-Oliva, which set sail from the Spanish city of Barcelona last month, include Irish Nobel Peace Prize laureate Mairead Maguire, Swedish and Algerian lawmakers, a South African Olympic athlete and a Malaysian doctor.
The all-female initiative seeks to break Israel’s decade-long blockade of the Gaza Strip and show solidarity with the women of Gaza.
Palestinian resistance movement Hamas, which has governed the enclave since 2007, condemned “the Israeli occupation’s assault on the aid ship and its intimidation of the activists on board”.
In a statement, Hamas spokesman Fawzi Barhoum said the incident amounted to “an act of state terrorism” and was another example of Israeli “aggression against the Palestinian people and those who show solidarity with the Palestinian cause”.
Barhoum went on to urge the international community to “put an end to Israel’s crimes” and stressed the need for immediate action to “lift the blockade and rescue the people of Gaza”.
In June last year, Israeli forces intercepted the Marianne -- which had been taking part in a similar initiative -- and arrested all the activists on board.
Another aid mission ended in tragedy in 2010 when the Mavi Marmara, a Turkish ship, was raided by Israeli commandos who killed 10 Turkish activists.
Since 2007, Gaza has faced a crippling Israeli and Egyptian blockade that has deprived its almost 2 million inhabitants of most basic commodities including food, fuel, medicines and building materials.
In June, UN Secretary General Ban Ki-moon described the blockade of Gaza as “collective punishment” that “suffocates its people, stifles its economy and impedes reconstruction efforts”.