Boat disaster in Libya leaves another 20 people dead

Four shipwrecks in space of three days claim lives of more than 110 people in Mediterranean

A humanitarian worker speaks with a survivor from a shipwreck off the coast of Libya near the port of al-Khums on November 12 (AP)

A wooden boat carrying migrants bound for Europe has capsized off the Libyan coast, killing 20 people, an international humanitarian charity has said.

Only three women could be rescued by local fisherman with the rest of the boat inhabitants all drowning near the town of Sorman.

It came just hours after another shipwreck claimed the lives of at least 74 migrants in the Mediterranean Sea.

Four shipwrecks in the space of three days have now claimed the lives of more than 110 people who have tried to make the perilous crossing from the North African country.

A statement from Doctors Without Borders (DWB) said: “They were in shock and terrified; they saw loved ones disappear beneath the waves, dying in front of their eyes.”

The wooden boat was carrying 23 migrants who had departed from the Libyan coastal town of Sorman.

One of the three survivors lost her husband, her sister and her sister's one-year-old child, a spokesman for DWB said.

Alarm Phone, an independent group that supports rescue operations in the Mediterranean Sea, tweeted that the boat had called for rescue before it sank.

The group said it "repeatedly" requested a search-and-rescue operation. "In vain. They decided to let them drown. Our hearts are broken," the group tweeted.

On Thursday, the UN migration agency said at least 74 migrants had drowned when their boat capsized off the coast of the Libyan port of al-Khums.

Only 47 people were rescued by the Libyan coastguard and fishermen and brought to shore.

In the years since the 2011 uprising that ousted and killed longtime dictator Muammar Gaddafi, war-torn Libya has emerged as the dominant transit point for migrants hoping to get to Europe from Africa and the Middle East.

Smugglers often pack desperate families into ill-equipped rubber boats that stall and founder along the perilous Central Mediterranean route. At least 20,000 people have died in those waters since 2014, according to the International Organisation for Migration.

In recent years, the EU has partnered with Libya's coastguard and other local groups to stem the dangerous sea crossings, but rights groups say those policies leave migrants at the mercy of armed groups or confined in squalid detention centres rife with abuse.