The Arab world has seen a spate of self-immolations since Mohamed Bouazizi, a Tunisian vendor, sparked a revolution when he set himself alight on December 17 to protest the seizure of his merchandise.
Yacoub Ould Dahoud set himself on fire on Monday inside his car in front of the Senate in Nouakchott died, his family said Saturday
He had alerted journalists that he intended to carry out the act because he was "unhappy with the political situation in the country and angry with the government."
Mauritanian President Mohamed Ould Abdel Aziz had little sympathy for Ould Dahoud.
"Frustration and distress led this rich man to act against a government that is in a merciless fight against waste and the misappropriation of public funds," he said during a visit Thursday to a poor district in the capital.
"The man who tried to commit suicide is a businessman from the wealthy class and so is not part of the poor, disadvantaged citizens who have been victims of injustices for 50 years," he added.
The Mauritanian president said that the situation in his country was "completely different" from the situation in Tunisia and other parts of the Arab world where there have been similar protests.
"We have a free opposition that criticizes and does its work. Our opposition raises all issues. We don't have taboos," he added.
Eight Algerians and 10 Egyptians have also torched themselves and two more cases were reported in Morocco Saturday, one in Smara, western Sahara, and the other in Mellal, in the centre of the country.
The reports indicated they were symbolic gestures, with witnesses and local authorities saying the man in Smara was unharmed and the one in Mellil, an itinerant trader, was burned on one hand.
Bouazizi's fatal act in Tunisia unleashed weeks of protests against unemployment, rising food costs and the autocratic rule of president Zine El Abidine Ben Ali, who was finally forced out and fled to Saudi Arabia.