After an unexpected coup three years ago in neighbouring Gabon, which toppled the Bongo dynasty sending shockwaves across the continent, Cameroon immediately reshuffled its military leadership.
Then, while running for a controversial eighth term in power at last year’s presidential election, Biya reshuffled the top brass of the army.
Again in June this year, he promoted several members of the defence and security forces to higher ranks.
The circumstances under which the latest changes were made have sparked debate, especially among social media users.
Biya made the appointments in separate decrees on Monday from the Swiss city of Geneva, where he has been staying since leaving Cameroon on 7 June for what his team described as a “brief private stay”.
Many in Cameroon have criticised the lack of information about his activities and the uncertainty surrounding the duration of his foreign trip.
After last year’s election, he promised to name a new cabinet, but has yet to do so. A new post of vice-president that was created this April remains unfilled.
During his nearly 60-day period abroad so far, he has signed several other decrees, including some authorising his government to sign loan agreements with international financial institutions.
His absence sparked further speculation about his health, but the government has continually debunked reports that the head of state has been in hospital.
Press freedom groups were outraged when it was announced two years ago that the media in Cameroon were banned from reporting on Biya’s health.
Cameroon’s Communication Minister RenĂ© Emmanuel Sadi has said the president is alive and will be returning to the country soon, during an interview with French-language broadcaster RFI.
He also dismissed allegations by the opposition that the nonagenarian leader’s absence amounted to a vacancy at the helm of the state, saying Biya continues to work from Geneva.
But President Biya’s continuing absence means Cameroon has a “glaring institutional vacuum”, says the opposition CRM party’s vice-president, Mamadou Mota.
“A country cannot be governed by remote control while critical socioeconomic challenges go unaddressed,” he said last week.
Additional reporting by Natasha Booty