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.
Trump says text of signed US, Iran deal will be released on Friday
President Donald Trump has announced on Monday that a preliminary agreement to end the war in the Gulf has been signed by the US and Iran, though details have yet to be made public and both countries said a permanent truce is yet to be negotiated.
India curbs Telegram use over medical exam fraud concerns
India has blocked the Telegram messaging app until June 22, saying the platform has been used to "defraud candidates" taking a national medical entrance examination, the Ministry of Education said in a statement on Tuesday.
Red Cross says Congo Ebola epidemic yet to peak, may last a year
A Red Cross official said on Tuesday that the Ebola epidemic in eastern Democratic Republic of the Congo had not yet peaked, and could last for a year.
Lebanon fighting eases after US-Iran deal but displaced warned not to rush home
Fighting in southern Lebanon eased on Monday after the US-Iran deal to end the wider conflict was announced, but an Israeli drone strike killed one person and authorities warned displaced people not to rush home as Israel said it would keep troops in the south.
Ukraine's Zelenskyy says he offered to meet Putin at G7 or the US
Ukrainian President Volodymyr Zelenskyy has said on Monday that he had offered to meet Vladimir Putin at a G7 summit in France this week or even in the United States for talks to end a four-year war.
