Fourteen migrants have left a car carrier in Libya, but others have locked themselves in on a car deck as charities were allowed access.
Dragonet Shipping's 750-ceu Nivin (built 1983) hit the headlines this week when 93 people refused to leave after being rescued from a sinking boat and taken to the port of Misrata.
The charity Medecins sans Frontieres (MSF) said those who left on Thursday included a woman, her baby and five unaccompanied minors.
MSF added it had treated burns from petrol spills and witnessed "despair" on board.
Julien Raickman, MSF head of mission in Libya, said: "It’s a shame that once again the only response given to people in search of safety is prolonged arbitrary detention in the country they desperately attempt to leave.”
The United Nations High Commissioner for Refugees (UNHCR) told InfoMigrants on Thursday that migrants from Sudan and Bangladesh had voluntarily left the ship.
But one migrant told InfoMigrants: "They [coast guard] told us that if we did not go out, they would burn the boat."