Mauritanians are voting for the first time since the country gained independence from France in 1960.
The 62-year-old is standing down after serving the maximum two five-year elected terms.
However the status quo is likely to prevail when a new leader is elected.
Abdel Aziz has expressed his support for Mohamed Ould Ghazouani, who is a former general and defense minister.
Bahrain, Kuwait, Jordan face renewed Iranian attacks after US hits Iran's south
US forces bombed targets in southern Iran overnight after President Donald Trump said Tehran would pay dearly for the deaths of American soldiers, while Iran targeted US sites in Bahrain, Kuwait and Jordan and a tanker was hit in the Strait of Hormuz.
Lebanese army enters southern town after Israeli withdrawal, in first test of US-brokered deal
Lebanese army troops began deploying in the southern Lebanese town of Zawtar al-Gharbiyeh on Tuesday after Israeli forces withdrew from the area, a senior Lebanese security official said, in line with a US-brokered plan.
Kuwait lodges formal protest with Iran over tanker attack; ministry says power station fires contained
Kuwait's Ministry of Foreign Affairs today summoned Iranian Ambassador Mohammad Totonchi to deliver a formal protest note over Iran's targeting of the Kuwaiti tanker Kaifan in the Strait of Hormuz on Monday evening, which resulted in injuries to several crew members.
Russian attack kills three in Ukraine's Zaporizhzhia, officials say
A Russian guided-bomb attack on the southern Ukrainian city of Zaporizhzhia killed at least three people on Tuesday and injured more than a dozen, regional officials said.
Fires in Spain and France, hail in Balkans; Europe's erratic weather persists
Firefighters struggled to control Spain's biggest wildfire of the year on Tuesday and two firefighters were killed in a blaze in southwestern France as extreme heat persisted in Europe, with increasingly volatile conditions bringing drought and forecasts of severe hailstorms.
