Mauritania's main cities were shaken earlier this week by violent riots. Protests began after the death of a young black Mauritanian, Oumar Diop, who died hours after being arrested by police.
The authorities have appealed for calm and announced an investigation that includes the autopsy of Diop. These days of violence have exposed a fragility of Mauritania's social cohesion. Although banned since 1981, the slavery of Mauritanians of black African origin has left its mark on society.