Greece's coast guard says it is unclear how many people are missing from the latest migrant boat sinking off an eastern Greek island that has claimed at least 11 lives.

Ten people have been rescued from Thursday's sinking north of the island of Samos. The coast guard said the survivors were in shock and their accounts of how many people were on board were confused and vague.

Five of the survivors were found clinging to a piece of wood, leading authorities to believe that the vessel that sank was made of wood.

The bodies of our boys, three girls, three men and one woman were recovered from the sea. A search and rescue operation was ongoing in the area by the Greek coast guard and vessels from the European border patrol agency Frontex.