Barcelona  - Gabon's President Omar Bongo, 73, is in a serious condition at a clinic in Barcelona, Spain, the daily La Vanguardia reported Thursday.

Africa's longest-serving head of state has been at the clinic for more than two weeks, medical and diplomatic sources were quoted as saying.

"He is doing very badly," Spanish Foreign Minister Miguel Angel Moratinos said.

Bongo was reportedly suffering from a tumor the nature of which was not given.

The Quiron medical centre did not officially confirm the president's presence there.

Bongo had earlier temporarily suspended his activities, alleging mourning for his wife's death in March, according to Spanish reports.(dpa)