The mass abductions were part of a string of kidnapping for ransom attacks on Nigerian schools and colleges this year by heavily armed gangs known locally as bandits.
A gang had snatched more than 100 students from the Baptist school, and since then dozens have been freed or escaped.
But insecurity has worsened since criminal gangs emerged. Most of them are based in vast forests across Kaduna, Katsina, Niger and Zamfara states.
Nigerian gunmen have freed scores of students abducted from three schools in the northwest this year, officials said Friday, following a burst of sudden releases.
The mass abductions were part of a string of kidnapping for ransom attacks on Nigerian schools and colleges this year by heavily armed gangs known locally as bandits.
Nearly 100 pupils abducted from an Islamic seminary in Tegina, Niger State were reunited with their families on Friday after three months in captivity.
In a separate case, gunmen also released 32 more students kidnapped in July from a Baptist school in northwest Kaduna state, a church leader and family representative said on Friday.
A gang had snatched more than 100 students from the Baptist school, and since then dozens have been freed or escaped.
"The bandits released 32 more of the students today, Friday. We still have 31 in captivity and we have hope they will be released soon," Reverend Joseph Hayab, a representative for the families, told AFP.
"As with previous students, we had to pay ransom to have them freed but I don't want to reveal the amount."
Agriculture college
In neighbouring Zamfara State, another 18 students and staff were taken from an agriculture college earlier this month were also freed, state police said.
Nigeria's northwest and central states have been caught up in a surge in violence from heavily armed criminal gangs who loot villages, steal cattle and carry out mass kidnappings.
The violence has its roots in years-long tensions and tit-for-tat raids between farmers and nomadic herders over grazing land and water resources.
But insecurity has worsened since criminal gangs emerged. Most of them are based in vast forests across Kaduna, Katsina, Niger and Zamfara states.
President Muhammadu Buhari has ordered military operations and air strikes on bandit camps but attacks have not stopped. Some local governors have attempted amnesty deals with the bandits but most have failed.