At least three people have died in clashes between security forces and protesters days after Mauritania’s presidential election,authorities said.
An unspecified number of people were reported injured.
The Protests broke out in the capital and elsewhere across the country late on Monday after President Mohamed Ould Ghazouani was declared winner of the poll.
His comfortable victory in the first round gives the former army chief a second term in office.
But the second-placed candidate and renowned anti-slavery activist, Biram Dah Abeid, on Monday denounced what he described as “massive fraud” and claimed the result was falsified.
He promptly called for “peaceful demonstrations and peaceful gatherings”.
Authorities said security forces confronted demonstrators in the southern city of Kaedi, the country’s largest and an opposition stronghold with an overwhelming Black majority.
Demonstrations were held in the towns of Nouadhibou, Rosso Zoueirat and Boghe, all also Abeid strongholds.
Due to Monday’s clashes, mobile internet access was blocked as the authorities vowed to arrest those behind the violence.
The electoral commission, which includes representatives of political parties, has dismissed opposition claims about voting irregularities.
Ghazouani has been accused by his opponents of corruption and mismanagement, but remains popular among Mauritanians who see him as a beacon of stability.