A flotilla of boats headed for Gaza carrying 350 pro-Palestinian activists - including climate change campaigner Greta Thunberg - has departed from Barcelona.
Around 20 vessels displaying Palestinian flags left the Spanish port at 19:00 local time on Monday, stocked with medical and food supplies.
The flotilla first attempted to set sail on Sunday, but had to return to port due to stormy weather.
The aim of the mission is to 'break Israel's illegal siege on Gaza,' the organisers said - though a previous attempt to reach Gaza by sea was intercepted by Israeli forces.
The Global Sumud Flotilla Mission plans to launch in two waves - the first from Barcelona and the second from Tunis on 4 September.
Activists hope the boats will converge in the Mediterranean before sailing towards Gaza, a trip that is estimated to take seven or eight days.
'We are sailing again to break the siege and open up a humanitarian corridor,' Thunberg said in a video message.
Punk singer Bob Vylan, known for leading a controversial chant at Glastonbury, expressed support for the activists, calling them 'brave individuals' attempting to do what should have been done by governments long ago.
Israeli authorities previously characterized an attempted aid flotilla as a publicity stunt, claiming it offered no real humanitarian assistance. This follows a blockade based on accusations of smuggling and threats to national security in Gaza, leading to international concern over famine conditions reported in the area.
The departure coincided with ongoing discussions regarding humanitarian support and aid distribution systems in Gaza, further complicated by historical attempts to deliver assistance and their interception by naval forces.
