Nigerian President Bola Tinubu on Tuesday nominated former top military commander General Christopher Musa as new minister of defence as the country grapples with a wave of mass kidnappings.

Musa had been serving as chief of defence staff until October, when Tinubu sacked a slew of the country's top military brass following media reports of a coup attempt.

The ruling administration officially denied the reports of a coup plot.

Weeks later, the West African country was hit by a wave of mass kidnappings, including of hundreds of schoolchildren.

On Monday, Defence Minister Mohammed Badaru Abubakar resigned, citing health reasons.

Needs approval from Senate

The Defence Minister-nominee, Musa, will need to be confirmed by the Senate to take up his new post.

In a letter to the Senate, Tinubu "expressed confidence in General Musa's ability to lead the Ministry of Defence and further strengthen Nigeria's security architecture," according to a statement from the presidency.

In November, the mass abductions in Nigeria saw schoolchildren and teachers, worshippers and priests, a bride and her bridesmaids, farmers, women and children taken hostage.

In the largest attack, armed gangs kidnapped more than 300 teachers and staff at St. Mary's co-education school in north-central Nigeria on November 21. Fifty escaped, but the rest remain in captivity.

On Monday, Nigerian authorities promised the pupils would be home "soon".