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.
No evidence alleged Bondi gunmen received military training in Philippines
There is no evidence indicating that the two suspects involved in the Bondi Beach attack received any form of military training while in the Philippines, the country's National Security Adviser said on Wednesday.
At least 12 killed in Nigeria mining site attack
At least 12 people were killed and three others abducted when gunmen attacked a mining site in Atoso village in Nigeria's restive Plateau state, a local group leader said on Wednesday.
Russian attack on Ukraine's central Cherkasy injures six, causes blackouts
Russia launched a "massive" drone attack on Ukraine's central Cherkasy region, injuring six people and triggering a blackout in part of Cherkasy city, the local governor said on Thursday.
UN, aid groups warn Gaza operations at risk from Israel impediments
The United Nations and aid groups have warned on Wednesday that humanitarian operations in the Palestinian territories, particularly Gaza, were at risk of collapse if Israel does not lift impediments that include a "vague, arbitrary, and highly politicised" registration process.
Israel approves natural gas deal with Egypt, Netanyahu says
Israel has approved a deal that will supply natural gas to Egypt, Israeli Prime Minister Benjamin Netanyahu said on Wednesday, describing it as the country's largest-ever gas deal.
