Nigeria’s President Muhammadu Buhari has nominated four former military commanders for ambassadorial roles after their resignation last week.

The president overhauled the military's top command amid growing calls for a reshuffle due to insecurity across the country.

He accepted the resignation of the chief of defence staff and the heads of the army, navy and air force respectively and approved their retirement from service.

On Thursday he forwarded their names to the senate for approval for the diplomatic posts. The senate is likely to approve their nominations.

Nigeria has been struggling to deal with the decade-long Boko Haram insurgency in the north-east, as well as kidnappings and banditry across the country.

The president has also extended the tenure of the inspector general of police by three months.