The people were held in different locations, including farms, houses and warehouses, said UNHCR spokesperson Andrej Mahecic at a UN media briefing.

“Libyan authorities estimate that an additional 6,000 migrants and refugees are still being held by smugglers,” said Mahecic.

If confirmed, this would bring the total number of refugees and migrants held in Sabratha to 20,500, including those in official detention centers.

“UNHCR colleagues on the front lines describe a picture of human suffering and abuse on a shocking scale,” said Mahecic.

Sabratha is some 80 km west of Tripoli and is a main departure point for migrant boats attempting to make the perilous journey across the Mediterranean Sea to Europe, the UN migration agency International Organization for Migration (IOM) said.

UNHCR’s Mahecic said that among those who suffered abuse at the hands of smugglers, are pregnant women and new-born babies.

“Hundreds of people were discovered with no clothes or shoes. Scores of them are in need of urgent medical care, with some suffering from bullet wounds and other visible signs of abuse,” said the UNHCR spokesperson, adding “Refugees and migrants who were rescued from the smugglers are visibly traumatized.”

According to the spokesperson, most of the victims said that they were subjected to numerous abuses, including sexual and gender-based violence, forced labor and sexual exploitation.

The refugees and migrants were taken to a hangar in the Dahman area in Sabratha serving as an assembly point since the onset of the crisis.

From there authorities are transferring them to official detention centers where humanitarian agencies are providing lifesaving assistance.

IOM spokesperson Joel Millman said his agency strongly advocates for alternatives to detention.

He quoted Othman Belbeisi, IOM Libya chief of mission as saying, “We are concerned about the large number of migrants transferred to detention. The centers are overcrowded and the conditions do not meet the minimum international human rights standards.”