France has condemned the attempt by soldiers to overthrow the government in its former colony Gabon and advised its citizens to avoid the capital, Reuters news agency reports.

"We condemn any attempt to change government outside constitutional rules," French foreign ministry spokeswoman Agnes von der Muhll said in a statement seen by Reuters news agency.

"Gabon's stability can only be ensured in strict compliance with the provisions of its constitution."

Journalists have pointed to the close and personal links between Gabon's elite families as evidence of powerful networks of patronage. African news site Jeune Afrique has branded them "fiefdoms" (in French).

Under former President Omar Bongo - the father of the current president - Gabon was seen by critics as a key part of the shadowy "Françafrique" network.

The term refers to allegations that France has covertly intervened to support African dictatorships and overthrow unfriendly governments if it served French interests.