Mauritania's supreme court on Tuesday ordered that a group of anti-slavery activists including a former presidential candidate be set free after downgrading the crimes of which they were found guilty in 2015.

"The Mauritanian supreme court ordered that Biram Ould Dah Ould Abeid and Brahim Ould Bilal be freed," Brahim Ould Ebetty, a lawyer for two of the men, told AFP. They were convicted of public order offences relating to a campaign against the problematic issue of slavery practices that persist in the country.