Israeli naval forces on Sunday intercepted a ship bound for the blockaded Gaza Strip, according to organizers.
"#FreedomFlotilla boat carrying medical supplies for #Gaza hijacked by Israeli forces," the Freedom Flotilla Coalition said on Twitter.
It called for a "safe passage for all on board #AlAwda (The Return) and speedy delivery of our solidarity gifts to the Palestinians of Gaza".
Israeli military spokesman Avichay Adraee confirmed the ship seizure by Israeli forces.
"A while ago, a naval operation ended during which a ship sailing from Europe with the aim of violating a naval blockade imposed on Gaza was captured," he said on Twitter.
"The ship has been tracked and captured in accordance with international law," he added.
Earlier on Sunday, Adham Abu Silmiyya, a spokesman for the National Authority for Breaking the Siege on the Gaza Strip, said contacts with the two-ship flotilla bound for Gaza had been lost.
"The Israeli naval forces are likely to have seized the ships," he told Anadolu Agency.
A statement by the Freedom Flotilla Coalition, which organized the trip, also said Israeli forces had contacted the vessel as it sailed 49 miles near to Gaza shores.
According to the statement, Israeli soldiers warned activists on board against approaching the Gaza shores, threatening to use force, if needed, to stop the ships.
The Gaza-bound flotilla had set sail from Norway on May 15 under the slogan "Right to a Just Future for Palestine" as part of a campaign to break an 11-year Israeli siege on the Gaza Strip.
Some 36 activists from 15 countries were on board of the two ships, which had been set to reach Gaza shores later Sunday.
By the end of 2016, nearly two million Gazans were depending on international aid in order to survive while nearly half of the families in Gaza lacked access to secure food supplies, according to the UN's Office for the Coordination of Humanitarian Affairs.
Every year for eight years now, the Freedom Flotilla Coalition has been launching a new campaign to challenge the Israeli siege on the Palestinian seaside enclave.
On May 31, 2010, Israeli commandos killed nine Turkish activists in the Mavi Marmara boat convoy in international waters. The convoy, which was part of the Freedom Flotilla Coalition, was headed for Gaza to deliver humanitarian aid. Another activist later succumbed to his injuries.
