Mauritania's President Mohamed Ould Abdel Aziz flies back to France Friday for medical tests less than a week after leaving, having undergone 40 days recovering from wounds received when a soldier shot him.

"I must return to France tomorrow for more analyses and X-rays following an appointment made earlier by the doctors," the 55-year-old president told a press conference late Thursday.

Abdel Aziz returned home last Saturday after 40 days in France after being shot in the intestines on 13 October.

Abdel Aziz was shot by Lieutenant Elhaj Ould H'Moudy, who was dressed in plain clothes, when his unmarked car failed to stop at a mobile army checkpoint.

H'Moudy has said it was a mistake and has not been punished.

The opposition, which boycotted celebrations of the country's 52nd anniversary of independence from France on Wednesday to protest against Abdel Aziz's regime, has demanded further investigation.