KHOMS (AFP) - Twenty migrants have died in a shipwreck off the Libyan coast, Doctors Without Borders (MSF) said, raising to almost 100 the death toll from two such Mediterranean tragedies the same day.

MSF teams in the north-western city of Sorman "assisted three women as the lone survivors of another shipwreck (Thursday) where 20 people drowned", the group said on Friday (Nov 13) on Twitter.

"Rescued by local fishermen, they were in shock and terrified; they saw loved ones disappear beneath the waves, dying in front of their eyes," MSF said.

Earlier, the UN's International Organisation for Migration (IOM) reported "a devastating shipwreck which claimed the lives of at least 74 migrants today off the coast of Khoms", a port city east of Sorman.

It said 47 survivors had been brought back to shore and 31 bodies retrieved, adding that the boat was reported to be carrying more than 120 people.

Seven women were among the survivors, Mr Mokhtar Salem Mohamed from Libya's interior ministry told AFP at a migrants centre in Khoms, some 120km east of the capital Tripoli.

Bodies from that shipwreck were lined up grimly along the beach on Thursday, some still wearing life jackets.

Traumatised survivors sat in shock on the shore, while others huddled under blankets as aid workers distributed food parcels.

One of the migrants spoke of the tragedy to AFP.

"Our boat sailed from an area near Tripoli two days ago," said Mr Koni Hassan, from Ghana, adding that the engine "broke down yesterday" resulting in the shipwreck.

"There were 120 people on board... many have died," he added.

The two shipwrecks sparked calls for an end to the conflict in Libya, where human traffickers have taken advantage of persistent violence since the 2011 overthrow of dictator Muammar Gaddafi.

The oil-rich North African country has become a key embarkation point for migrants, mostly from sub-Saharan Africa, attempting death-defying voyages to Europe to flee war and poverty at home.

While many have drowned at sea, thousands have been intercepted by the Libyan coastguard, which has been backed by Italy and the European Union, and returned to Libya.

They mostly end up in detention, often in horrific conditions.

'Horrific tragedy'

The United States embassy to Tripoli said the shipwrecks amounted to "another horrific migrant tragedy - another reminder of the need for a settlement to the #Libya conflict now in order to focus on the prevention of tragedies like this".

European ambassador Jose Sabadell said: "We need to work together to prevent these horrific events from happening again."

So far this year, more than 900 people have drowned in the Mediterranean trying to reach European shores, it said.

More than 11,000 others have been returned to Libya, it added, "putting them at risk of facing human rights violations".

The IOM said on Friday that "many women and children" were aboard the two boats, adding that the body of a toddler was among those retrieved.

"Staff in the region reported that more bodies continued to wash ashore overnight," IOM added.

The UN agency called for "a change of approach to Libya and the most dangerous maritime route on earth that ends the return of migrants to the country" and establishes "predictable safe disembarkation mechanisms".

On Friday, Italy's coastguard said it had rescued about 170 migrants on two separate rubber boats in Mediterranean waters, and took the people to the Italian island of Lampedusa, which lies north of Libya.