Mauritanians on Saturday cast their ballots in the run-off to the parliamentary and local elections held early this month.
The second round of parliamentary elections is taking place in 12 constituencies out of a total of 49.
The run-off polls are also taking place in 108 municipal districts.
The voting began at 7.00 a.m. local time (0700GMT) and is expected to end at 7.00 p.m. (1900GMT).
Unofficial results released early this month showed that the Union for the Republic (UFR) party, led by President Mohamed Ould Abdel Aziz, won the first round.
Some 1.4 million people were eligible to vote in Mauritania's parliamentary and municipal polls, which were held in the absence of international observers.
Some 98 Mauritanian political parties are vying for seats In the country’s 146-member legislative assembly and numerous municipal councils.
Opposition figures have questioned the integrity of the electoral process.