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.

Organisers, who gathered on Wednesday at the foundation of late South African leader Nelson Mandela 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 mobilise the … global community to join forces with us.”

Israeli officials repeatedly denounced last year’s mission, and previous smaller-scale attempts to reach Gaza by sea, as publicity stunts.

Israel, which controls all access to the Gaza Strip, denies withholding supplies for its more than 2 million residents. Palestinians and international aid bodies say supplies reaching the territory are still insufficient, despite a ceasefire reached in October which included guarantees of increased aid.

Following the ceasefire, Israeli forces now control more than 53% of the Gaza Strip where they have ordered residents out. Nearly the entire population is crowded into a narrow strip along the coast, mostly living in makeshift tents and damaged buildings.

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.”