A record 98 parties will take part in legislative, regional and local elections for which more than 1.4 million people are registered. Potential run-off elections would take place on September 15.
After a turbulent campaign, Mauritania—a northwest African frontline state in the Sahel's fight against terrorism—heads to the polls on Saturday for triple elections that will test head of state Mohamed Ould Abdel Aziz's record seven months before a presidential vote.
Military personnel cast their votes Friday to free themselves up to provide security in the vast and arid west African state with a registered electorate of some 1.4 million.
Polling booths opened at 0700 GMT and will close 12 hours later with first results not expected until the middle of next week. There will be no international observers.
Unlike in the last polls which it boycotted in 2013, the opposition is standing in the legislative, regional and local elections in which a record 98 parties will take part.
Potential run-off elections would take place on September 15.
The man in charge
Aziz, 61, came to power in a coup in 2008. He was elected in 2009 and again in 2014 for a second five-year term.
He has been frequently accused by opposition figures and NGOs of rights abuses, including the arrest of a former senator and the "secretive" detention of a blogger.
Although Aziz has said several times he will not seek a third mandate, something that would be against the country's constitution, statements by his ministers and supporters have allowed opposition suspicions to flourish.
Final campaign rallies drew sparse attendance despite the opposition shelving its boycott.
Aziz has slammed opposition leaders as "villains" and "troublemakers."
He has described some as "dangerous Islamists, racist extremists and the leftovers of former regimes which brought the country to its knees."
"We must keep them far from office with a massive vote for the UPR," his Union for the Republic party, which he vowed would "continue on the path of high achievement and the fight against mismanagement."