Activists behind a flotilla intercepted at sea last year by Israel while trying to bring aid to Gaza will try again this year, expecting more than twice as many boats carrying up to 1,000 medics, they said on Thursday.

The Israeli military halted the roughly 40 boats in the Global Sumud Flotilla last October as they attempted to reach blockaded Gaza, arresting Swedish activist Greta Thunberg and more than 450 other participants.

Organizers, who gathered on Wednesday at the foundation of Nelson Mandela, the late South African leader, in Johannesburg, said they hope to bring 100 boats for their next attempt.

"It is a cause ... for those that want to rise and stand for justice and dignity for all," Mandela's grandson Mandla Mandela, who was among activists detained last time, told the gathering. "We want to mobilize the ... global community to join forces with us."

Swedish activist Greta Thunberg departs on the Global Sumud Flotilla, a humanitarian expedition to Gaza, from the port of Barcelona, Spain August 31, 2025
Swedish activist Greta Thunberg departs on the Global Sumud Flotilla, a humanitarian expedition to Gaza, from the port of Barcelona, Spain August 31, 2025 (credit: REUTERS/NACHO DOCE)

Flotilla initial comprised dozens of vessels, hundreds of activists

Initially, the Global Sumud Flotilla set sail in late August, 2025, comprising dozens of vessels and hundreds of activists from multiple countries.

From the outset, its organizers argued that the flotilla’s humanitarian goals and maritime-law protections justified the attempt to bring aid.

Israel’s navy subsequently intercepted the flotilla in early October, detaining more than 400 participants.

The first wave of 41 vessels was intercepted on October 1, 2025, with a second wave of nine vessels intercepted about a week later.

Following the detention of the activities, Israeli prosecutors said the flotilla was “unprecedented in scale and scope... organized and centrally-directed...” and that its “movement resembled military vessels sailing in formation.”

Israeli officials repeatedly denounced the mission and previous smaller-scale attempts to reach Gaza by sea as publicity stunts.

If the flotilla is blocked again, the activists said it would still be worth it to highlight Gaza's plight.

"We may not have reached Gaza physically (but) we have reached ... the people in Gaza," said one of the activists, Susan Abdallah. "They know that we care, that we will not stop at anything until we actually break the siege."

Sarah Ben-Nun contributed to this report.