At least eight African migrants, and possibly as many as 27, died in a new boat tragedy off the coast of Libya, a search and rescue organisation said Monday.

French charity SOS Mediterranee said its boat, the Aquarius, had rescued 108 migrants from a stricken dinghy in high seas on Sunday.

One of the survivors told the Aquarius crew there had been at least 135 people on board when the overcrowded vessel left the Libyan port of Sabratha.

Eight of the passengers were confirmed dead: six corpses were recovered in the dinghy and two were carried away by the waves after a mass panic resulted in dozens falling into the water as the rescue boat approached.

The dinghy, at that point, was already half-deflated and taking on water with the motor having given out some nine hours after it embarked from Libya on Sunday.

The survivors were nationals of 11 different African countries.

According to the International Organisation for Migration, a total of 352 migrants perished in the waters between Libya and Italy between the start of this year and April 15.

More than 24,000 migrants have made it to Italy, almost all of them having been picked up at sea by boats participating in a multinational search and rescue operation coordinated by the Italian coastguard.

SOS Mediterranee operates the Aquarius in partnership with medical charity Doctors without Borders (MSF). Sunday's operation came a day after the boat rescued 116 migrants from another stricken dinghy, three of whom had bullet wounds.