The Ocean Viking charity ship rescued more than 80 migrants off the coast of Libya on Saturday, according to Doctors without Borders (MSF), which operates the vessel along with the French charity SOS Mediterranee.
The migrants, mainly Sudanese men and adolescents, were picked up after the Ocean Viking rescued 85 people including four children on Friday.
The white rubber dinghy was spotted after a plane was seen repeatedly flying over it, MSF mission head Jay Berger said.
European forces regularly patrol the central Mediterranean looking for boats leaving the Libyan coast, particularly during mild weather.
The Ocean Viking sailed towards the area where the plane seemed to be focusing on and found the dinghy, Berger said.
"But the plane never tried to communicate with us," he added.
Some 170 migrants, all from sub-Saharan Africa, are now on board the Ocean Viking, which left Marseille on Sunday. An AFP journalist is also on board.
Italy's far-right Interior Minister Matteo Salvini, who .
