Tunisian authorities repatriated nearly a hundred migrants from sub-Saharan Africa on Tuesday under a so-called "voluntary return" initiative that has involved almost 5,000 people over the past year, Tunisia's national guard said.

With their backpacks and suitcases, dozens of individuals -- mostly young men, their faces covered in black masks, alongside a number of women and children -- were photographed by AFP at the Tunis-Carthage airport.

A total of 91 irregular migrants left Tuesday, headed to multiple sub-Saharan countries, national guard spokesman Houcem Eddine Jebabli told AFP, lauding the strength of a programme launched last July.

He said the government initiative "takes into account humanitarian and social aspects alongside judicial and security constraints", adding that "so far close to 5,000 people" have participated in the programme.

The rate of returns has intensified recently, with flights increasing in frequency from once a month to "near-daily dedicated flights", Jebabli added. The initiative is separate from the International Organization for Migration's own voluntary return scheme, which Jebabli said "secured the return of 27,000 people in three years".