The Coordination of Democratic Opposition (COD), an umbrella organisation for around 10 political parties, called in a statement for "the whole truth to come out and be made public on the circumstances of the incident."
Aziz was shot and wounded when soldiers opened fire on his convoy near the northwestern African country's capital Nouakchott. He was flown to a hospital in Paris on Sunday. Aziz himself said that the shooting "was committed in error by a military unit" but the incident left many in Mauritania and abroad wondering whether the president was targeted.
The Alliance for Justice and Democracy, another opposition group, said a probe was needed "to establish how such a serious failure, that put the president's life in danger, was possible."
Mauritania has been hit by chronic unrest over the years. Aziz himself came to power in a coup in 2008 and he has received death threats from Al-Qaeda's North Africa branch, which he has vowed to eradicate.