Greta Thunberg gave a rousing speech before boarding a humanitarian aid flotilla to Gaza, the second attempt at delivering aid to Palestinians this year. Before leaving Barcelona the climate campaigner called out world leaders for “betraying and failing Palestinians and all oppressed peoples of the world.” Thunberg and other activists failed to break Israel's longstanding naval blockade of Gaza in June but were captured and deported. The flotilla will be joined by more boats setting off from Greece, Italy and Tunisia before sailing to Gaza.

Earlier this year the activist was detained by Israeli forces along with 11 others after they attempted to sail from Italy to Gaza to deliver a symbolic amount of aid.

Unspecified number of vessels due to depart Barcelona on Sunday, with dozens more expected to leave other Mediterranean ports on 4 September