Cameroon's President Paul Biya has promoted several army officers to the rank of general, days after announcing his bid for an eighth term in elections scheduled for October.

In a decree announced on Tuesday, Biya promoted a colonel of the national gendarmerie and five army officers to the rank of Brigadier General.

He also promoted a captain of the national navy to the rank of Rear Admiral.

Biya, 92, has been in power for 43 years and his capacity to govern have become the subject of debate. But he declared that “the best is yet to come” as he announced his bid on Sunday for a fresh seven-year term.

He is already the de facto presidential candidate of the Cameroon People's Democratic Movement (CPDM), of which he is party leader.

Several of his longstanding supporters have appeared to distance themselves from him in recent months, and there have been two high-profile defections from Biya's camp in recent weeks.