Nigerian President Goodluck Jonathan has replaced his chief of defense and the heads of the country's army, navy and air force.
A statement Thursday gave no reason for the sweeping overhaul.
The move comes as Nigeria struggles with a four-and-a-half-year insurgency by the militant group Boko Haram. A bombing Tuesday in the group's home city of Maiduguri killed at least 43 people.
Mr. Jonathan is also dealing with major defections from the ruling People's Democratic Party, one year ahead of elections.
The president tapped Air Marshal Alex Badeh as the new chief of defense staff, replacing Admiral Ola Sa'ad Ibrahim.
Major General Kenneth Tobiah Jacob Mimimah is the new chief of army staff, Rear Admiral Usman Jibrin takes over the navy, and Vice Marshal Adesola Nunayon Amosu becomes the new head of the air force.