Italy's new far-right government has prevented 35 men from leaving a migrant ship which has been requesting access to an Italian port for two weeks.
Minors and people with medical issues were allowed to disembark in Sicily.
The Humanity 1 was one of four vessels carrying migrants waiting for permission to dock in Italy.
The new Italian Prime Minister, Giorgia Meloni, has promised to crack down on migrants travelling across the Mediterranean from North Africa.
Italy is one of the main entry points into Europe and since the start of the year 85,000 migrants have arrived on boats, according to the UN.
Many of the migrants set sail in small boats and are rescued by charity vessels during their journey.
In total 144 people were allowed to disembark the Humanity 1, which sails under a German flag, on Sunday morning.