Libya's navy said it retrieved the bodies of three would-be migrants and rescued almost 100 others after their boat sank on Thursday.
"One of the migrants called us on a satellite telephone to tell us that their boat was about to sink off Garabulli," east of Tripoli, navy official Issa Zarruk told AFP.
"We have saved more than 90 migrants. Three have died probably from suffocating in the panic that ensued on board the boat."
The Libyan navy was seen taking the survivors ashore in dinghies.
Thousands of Africans seeking asylum or a better life in Europe have died in recent years trying to make the journey from Libya across the Mediterranean Sea.
Warmer weather prompts a surge in migrants each year, and thousands of people have landed on Italian shores, where processing centres are already saturated, notably in Sicily.