Mauritanians voted on Saturday to choose 36 lawmakers in the second round of legislative elections dominated by the ruling party that sparked allegations of foul play.
The El Insaf party of President Mohamed Ould Cheikh El Ghazouani, who has been in power since 2019, picked up 80 seats in the 176-seat legislature in the first round on 13 May.
Smaller groups allied to the president picked up 36 seats, while the opposition won 24, nine of which went to its biggest formation, the Islamist movement Tewassoul.
Voting in the second round began at 07:00 (local and GMT) on Saturday and is due to end 12 hours later.
The results are expected to be announced in the next few days.
All the candidates in the fray on Saturday are from constituencies outside the capital Nouakchott.
Opposition figures have called for a rerun of the first round, citing what they call electoral fraud and other problems.
"The government's attitude is dragging us decades back into the past, and constitutes the death knell of democracy," said Messaoud Oud Boulkheir, head of the APP, one of several traditional opposition parties that have been wiped out in parliament.
In local voting which also took place on 13 May, El Insaf won all 13 regional councils that were at stake and 165 out of 238 councils.
The official turnout was 71.8 percent.
Ghazouani, a 66-year-old former army chief, is considered one of the main architects of Mauritania's success against jihadism in the violent Sahel.