Nigeria has evacuated from Mali 104 of its citizens, mostly women, either made to work as "sexual slaves" or suspected of involvement in human trafficking, officials said on Tuesday.

The National Agency for the Prohibition of Traffic in Persons (NAPTIP) evacuated 93 alleged victims of human trafficking, nine suspected traffickers and two babies, the agency's head, Beatrice Jedy-Agba, told reporters.

The babies, aged between six months and a year, were born in Mali, she added.

Jedy-Agba said they were brought back home on Saturday after investigations by the agency showed that "Nigerian girls are sold for about two million naira ($12,600, 9,200 euros) each and made to work as sexual slaves."

The investigations started in September last year, she said.

Many brothels in the capital Bamako and the cities of Mopti (centre), Kayes (west), Sikasso (south) and Gao (northeast) were populated by mostly Nigerian girls, victims of human trafficking, aged between 14 and 17 years, Jedy-Agba explained.

NAPTIP found out that thousands of Nigerian citizens have been deceived and transported to the francophone west African nation on the pretext that they would be taken to Europe.

"Some of them in their hundreds are deported from Algeria and Morocco back to Mali after failed attempts to cross to Europe," she stated.

The agency has started the process of their rehabilitation and reintegration into the society for the victims, while the suspected traffickers would be prosecuted after their interrogation.

One of the suspected traffickers is a man, she said.