At least 41 people, who were wearing life jackets, have been rescued and 63 people remain missing, a spokesperson for the Libyan Navy said.
More than 1,000 people have drowned in the Mediterranean this year sailing from Libya to Europe, with a rush in the past few days to beat an anticipated crackdown by the European Union, the International Organisation for Migration said.
Around 204 people have died in recent days after being packed into unsafe vessels by smugglers, with 103 lost in one incident on Friday.
IOM spokesman Leonard Doyle said the surge in recent days may be due to factors including weather and the end of Ramadan.
“But also there is a recognition I think worldwide that the European Union is starting to manage the process better so maybe they equally are trying to profit while they can. Smugglers will always put profit before safety,” he said.
The effort to reduce people-smuggling has hinged in part on developing a coast guard for Libya that returns migrants caught off shore.
Between Friday and Sunday, close to 1,000 migrants were returned to the Libyan shore by the Libyan Coast Guard. So far this year, the coast guard has returned about 10,000 to shore, where Libyan authorities transfer them to detention centres.
Agencies contributed to this report