The group includes 27 students, three teachers and nine family members, the state government said in a note that mentions them all.
A student who died during the attack was called Benjamin Habila.
Governor of the State of Niger, Abubakar Sani Bello it closed all boarding schools in the region and sent military personnel to rescue the kidnapped from the school, according to its chief press secretary, Mary Noel Barje.
President Buhari condemned the kidnapping of school children.
“The president instructed the Armed Forces and the Police to ensure the immediate and safe return of all captives,” said Buhari’s spokesman, Garba Shehu, in a statement on Wednesday.
“The president also dispatched a team of chief security officers to Minna, state of Niger, to coordinate the rescue operation and to meet with state officials, community leaders, as well as parents and faculty officials.”
A former Nigerian senator, Shehu Sani, told CNN that the school has no perimeter fence and would have easy access to militants.
Sani, who was also a student at the school, told CNN: “The city is at the epicenter of the insurgency in the state of Niger. Fulani bandits operate within the axis and there are thousands of displaced people in this area. Bandits in northwest Nigeria are becoming more lethal and destructive than Boko Haram. ”
Buhari recently retired all heads of Nigeria’s security forces and appointed new ones amid growing insecurity and kidnappings in the country.
“The security situation in Nigeria is” overwhelming and threatens the country’s peace, “Sani told CNN.
“It is a pity that the heads of service have been allowed to stay for so long,” he added.