A flotilla carrying humanitarian aid and activists, including Swedish climate campaigner Greta Thunberg, is due to leave from Barcelona on Sunday to try to “break the illegal siege of Gaza”, organisers said.

The vessels will set off from the Spanish port city to “open a humanitarian corridor and end the ongoing genocide of the Palestinian people”, said the Global Sumud Flotilla.

They did not say how many ships would set sail or the exact time of departure. The flotilla is expected to arrive at the war-ravaged coastal enclave in mid-September.

“This will be the largest solidarity mission in history, with more people and more boats than all previous attempts combined,” Brazilian activist Thiago Ávila told journalists in Barcelona last week.