Around 100 schoolchildren kidnapped from a Catholic school in Nigeria last month were handed over to state officials on Monday, a day after authorities secured their release.

The children – many wearing football jerseys and girls in long robes – were driven into the Niger State Government House in white buses escorted by a dozen military vans and armoured vehicles.

Dozens of the 315 students and staff were abducted from the school Minna, in north-central Niger state. Fifty escaped shortly after the raid.

The fate of 165 others is still unclear but the state Governor Umar Bago said "I want to reassure parents and guardians of these children that they will be safely delivered to them and very soon."

Medical checks

"We wish to recover the remaining students that are still in captivity and by the grace of God in a very short time from now we are going to receive them," he said during an address to the students and officials.

The children will undergo medical checks before they are reunited with their parents, the governor added.

Bago shook hands with some of the children and led them into a hall where the state emir and local officials were seated to receive them.

"Today is fundamental and very important in redefining the history of this state," the state governor said.

Kidnappings for ransom

According to a list of the released children seen by AFP, most of those freed are aged between 10 and 17 years. The school catered for children as young as nursery school age.

It is unclear who seized the children from their boarding school in remote rural Papiri village or the circumstances surrounding the release of the 100.

Though kidnappings for ransom are common as a way for criminals and armed groups to make quick cash, a spate of mass abductions in November put an uncomfortable spotlight on Nigeria's security situation.

The news of their release broke on Sunday as Nigerian military intervened in neighbouring Benin conducting countercoup operations after a group of soldiers announced a coup bid in the former French colony.

Terrorist threat

The country also faces terrorist threat in the northeast, while armed "bandit" gangs conduct kidnappings and loot villages in the northwest.

In November, assailants across the country kidnapped two dozen Muslim schoolgirls, 38 church worshippers, a bride and her bridesmaids, with farmers, women and children also taken hostage.