Spanish aid groups say Spain has reluctantly allowed them to depart for the Greek islands where they want to deliver aid supplies to migrant camps. But the humanitarian aid groups face hefty fines if their boats venture into official search and rescue areas in the Central Mediterranean.

Spain had blocked the rescue boats from sailing, fearing they would anger Mediterranean countries like Italy if they roam around the ocean looking for and picking up migrants.

After four months of legal back and forth, the Aita Mari received the green light to sail to the Aegean Sea on Tuesday.

A separate boat, Proactiva's Open Arms, will depart from Barcelona later this week with blankets and other supplies, the group's founder Oscar Camps said Wednesday.

Camps said his group would still conduct rescues if they come across people in need.