At least 57 people are thought to have died after a boat carrying at least 75 African migrants capsized off the coast of Libya.
A UN migration official said 20 women and two children were amongst the dead.
Eighteen people were rescued and returned to shore by fishermen and Libya’s coast guard, Safa Msehli, a spokesperson for the International Organization for Migration, said.
The boat left the western coastal town of Khums, Libya, on Sunday, Ms Msehli said.
The survivors, who are from Nigeria, Ghana and Gambia, said the boat stopped due to an engine problem, but then capsized during the bad weather.
On Wednesday, at least 20 migrants went overboard from a vessel and were thought to have died, according to the UN migration agency.
There has been a rise in crossings and attempted crossings from Libya in recent months.
In the first half of this year, more than 7,000 people were intercepted at sea and returned to detention camps in Libya, Amnesty International said.
The number of migrants and refugees who died while attempting to reach Europe on dangerous sea crossings more than doubled so far this year, compared to the first six months of 2020 - according to a migration agency report earlier this month.
At least 1,146 migrants died between January and June - 741 died while trying to cross via the Central Mediterranean route between Libya and Italy.
Many migrants fleeing war and poverty in Africa and the Middle East have set out for Europe from Libya.
The country plunged into chaos after a Nato-backed uprising toppled and killed autocrat Moammar Gadhafi in 2011.
Survivors have spoken about abuse, including forced labour, beatings, rapes and torture in Libya's detention camps, according to rights groups and UN agencies.
The abuse often accompanies efforts to extort money from families before migrants are allowed to leave Libya on boats.