The activist group Sea Watch said in a statement they put up the banner early Wednesday to protest against the migration policies of the wealthy Western countries.
Thousands of people have drowned in recent years trying to cross the Mediterranean from poor, war-torn countries to the shores of Europe, AP reported.
Sea Watch and other NGOs are calling on leaders at the G-20 summit, which convenes in Hamburg in early July, to prevent further drowning deaths in the Mediterranean and develop concepts for legal migration.