Gabon’s Prime Minister Jean Eyeghe Ndong confirmed the death of 73-year-old President Omar Bongo on Monday, in a statement issued at a clinic in the Spanish city of Barcelona, where sources say Africa’s longest-serving ruler was being treated for cancer.

Gabon's President Bongo dead at 73 RFI report: Long-time leader Bongo confirmed dead What now for Gabon?

The declaration put an end to a flurry of controversial reports, which began with the announcement by French media late on Sunday that Bongo had died.

After news of Bongo's death was confirmed, officials in the West African nation announced a 30-day period of national mourning amid appeals for calm among the population.

Gabon's defence ministry, led by Bongo's son Ali Ben Bongo Ondimba, also announced the closure of air, land and sea borders, adding that measures had been taken to "secure sesitive administrative facilities and buildings".

Bongo, who became Africa’s youngest president in 1967 when he was elected at 31, had been receiving treatment in Spain for several weeks. Officially, this was for a check-up and to rest in the wake of his wife’s death in March. However, several sources -- including some from the hospital in Barcelona -- suggested his condition was severe. On May 6, the Gabonese presidency announced the “temporary suspension of [Bongo’s] functions”.

Media confusion

The apparent death of Bongo was first reported late on Sunday by the Web site of French magazine Le Point, quoting a source close to the Gabonese president’s entourage. The news was immediately seconded by AFP news agency, this time quoting a source close to the French government.

However, Gabon’s government spokesman Raphael N’Toutoume told French radio: "I am putting out a formal denial of this".

At 31, Bongo became Africa's youngest president following his election in 1967.File photo Bongo's wife Edith died in March of this year.AFP Gabon's ruler is also being investigated by a French judge for alleged embezzlement over the purchase of properties in France.File photo Bongo's subsequent re-elections have all been tarnished by allegations of fraud.AFP Bongo, here chatting with Angolan counterpart Jose Eduardo dos Santos, has played a key role in African politics. Gabon's ruler, pictured here with French ex-President Jacques Chirac, also nurtured close ties with France, the former colonial power. Bongo presided over vast development of Gabon's natural resources, including oil and timber. But the wealth derived from their exploitation has scarcely spread beyond the president's circle of friends. In 1994, Bongo was caught up in a ground-shaking corruption scandal involving French oil giant Elf and governments in France and Africa.

Later on Monday, Prime Minister Jean Eyeghe Ndong claimed Bongo was “indeed alive,” in a formal statement that also lambasted the “excesses of French media”.

A complicated succession

Despite government denials of Bongo’s death, stores and restaurants in the Gabonese capital of Libreville remained closed on Monday morning. There have been reports of people stockpiling food and rushing to petrol stations to fill their tanks in preparation for possible shortages in days to come. According to accounts gathered by the AFP, “the people are scared”.

The succession of President Bongo, who had been in power for the past 41 years, is expected to be a complicated affair.

The president’s son, current Defence Minister Ali Ben Bongo, appears best placed to succeed his father in the oil-rich African nation.

Since rising to the presidency in 1967, Bongo had maintained close ties with former colonial power France, though the relationship was recently frayed by a French inquiry into alleged corruption on the part of the Gabonese leader.

President Nicolas Sarkozy on Monday expressed sadness over Bongo's death, and said France was at its former colony's side during its time of grief.

"A great and loyal friend of France has left us," Sarkozy said, describing the 73-year-old leader as "a major figure in Africa and a head of state who had won the esteem and respect of his peers, especially for his many peace initiatives on the continent."