Nigerian President Umaru Yar'Adua has ordered the retirement of 40 top army generals, and has appointed new officers to take their place.

A Nigerian defense spokesman, Colonel Mohammed Yusuf, says the retirements are part of a normal process, and that the generals have all reached retirement age. The generals include the commanders of all five divisions of the Nigerian army.

The order comes five days after President Yar'Adua, who was inaugurated in May, announced his new Cabinet.

His predecessor, Olusegun Obasanjo, also retired a number of generals when he took power in 1999.

Nigerians lived under 16 years of military rule before a new constitution was adopted in 1999, and a peaceful transition to civilian government was completed.

The nation is experiencing its longest period of civilian rule since it achieved independence in 1960.

Mr. Yar'Adua was declared the winner of April elections that local and international observers say were severely marred by fraud. Nonetheless, the elections represented the Nigeria's first civilian-to-civilian transfer of power.

The new president has tried to ease the ensuing anger by making sure his Cabinet has representatives from all of the country's interest groups.

Some information for this report was provided by AP.