President Bongo was taken ill during a trip to Saudi Arabia last week and is receiving treatment in a hospital there.

Spokesperson Ike Ngouoni said the fatigue is a result of "extremely high levels of activity in recent months".

He also called on Gabonese to stay vigilant over fake news about the president's health circulating on social media and online, saying the presidency would update people regularly.

The government tweeted this video (in French) on Sunday evening:

République Gabonaise?@PresidenceGA

 L’intégralité de la déclaration du Porte-Parole de la Présidence de la République Gabonaise ce dimanche 28 octobre 2018 sur l’état de santé du Président de la République Ali Bongo Ondimba.

https://twitter.com/PresidenceGA/status/1056651984634347520

9:00 PM - Oct 28, 2018

Mr Bongo, who is 59, took over the presidency following the death of his father Omar Bongo in 2009.

Omar Bongo became president in 1967.