Libya on Tuesday repatriated nearly 200 illegal migrants from Niger who had been held in detention centres in the capital, an AFP photographer said.
They were flown home from Mitiga airport east of Tripoli, in coordination with the International Organization for Migration.
Hosni Abu Ayana, a spokesman for Libya’s office that deals with illegal migrants, said the repatriated group included 50 women and four children.
He added that more than 900 other detained migrants will be repatriated in the coming weeks.
The IOM website said that in 2016, the organisation "supported 1,589 migrants to voluntarily return to their countries of origin" from Libya, giving priority to "the most vulnerable".
People smugglers have taken advantage of the chaos gripping Libya since the 2011 revolution to greatly boost their lucrative trade.
Most departures take place from the west of the North African country, usually heading for Italy, 300 kilometres away across the Mediterranean.
Europeans are considering measures aimed at blocking the arrival of thousands of migrants, alarming NGOs, which fear those stranded in Libya may suffer mistreatment.
In the absence of an army or a regular police force in Libya, several militias act as coastguards but are often accused themselves of complicity or even involvement in the people-smuggling business.