Hundreds of West African migrants who had been kept in Libya as possibly part of an underground slave trade are reportedly returning home, according to the CBC.

The world is outraged at what is being referred to as the modern-day slave trade, where migrants are being sold for as little as $400.

On Friday, 164 Nigerian immigrants went home, the latest group to be sent in an act of repatriation. The European Union, along with the International Organization for Migration, is currently assisting migrants in the country in an effort to return them to their homeland.

The first round of migrants, all from Niger, returned home on Wednesday. The move was part of a massive evacuation of 3,850 migrants over the coming days, according to the UN migration agency.

Over the next six weeks, the African Union has a goal of returning 20,000 migrants from Libya over the next six weeks. Libya faced condemnation after news broke of slave auctions occurring in the country. Upwards of 700,000 migrants are believed to be currently held in at least 40 detention camps across the country, the AU Commission chairman said.

The migrants are believed to have been smuggled into the country in an effort for a better life in Europe. Instead, thousands have been placed in detention camps where smugglers are selling them off as slaves.

A flight with 167 migrants, including men, women and children, returned to Guinea on Thursday, according to the UN migration agency. Some were reportedly beaten while being held in detention centers in Libya.