The migrants set off for Italy from the city of Sabratha, west of Tripoli, but their vessel overturned. They spent eleven days at sea without any food or water.
Fifteen migrants died and 10 others survived 11 days at sea after their boat capsized off the coast of Libya, the Libyan Red Crescent said on Tuesday, citing the survivors.
The migrants had set off for Italy from the city of Sabratha, west of Tripoli, but their vessel overturned and they came ashore in Misrata some 270 kilometres (170 miles) east of their departure point, said Red Crescent spokesman Baha al-Kawash.
The boat was thought to have been swept away by the current due to bad weather, Kawash said.
Tragic news of capsized migrant rubber boat north of Misrata. Only 10 survivors suffering from severe dehydration taken to detention centre, @IOM_Libya Doctors & emergency team on the way. Alarming we still do not see solid steps to address irreglar unsafe movements across MedSea— OTHMAN BELBEISI (@OthmanBelbeisi) December 4, 2018
The 10 survivors, who include two women, spent 11 days at sea without any food or water before reaching a beach in Misrata on Monday, said another member of the Red Crescent.
Two of the survivors were from Algeria and Egypt, and the rest were from sub-Saharan Africa, the source said on condition of anonymity.
They had suffered injuries and dehydration, and received medical treatment before being taken to a migrant detention centre in Misrata, said Kawash.
Three of the 15 dead migrants were women, according to the survivors.
The head of the Libyan office of the International Organization for Migration said the survivors of the "tragic" incident had suffered from severe dehydration.
Othman Belbeisi said an IOM medical team was on its way to tend to the survivors.
Plunged into chaos following the fall and killing of longtime dictator Muammar Gaddafi in a 2011 NATO-backed uprising, Libya has become a prime transit point for sub-Saharan African migrants making dangerous clandestine bids to reach Europe.
People smugglers have taken advantage of the turmoil, putting African migrants seeking to reach Europe at greater risk.
Many migrants, intercepted or rescued at sea, find themselves held in detention centres where they face dire conditions.