Nigerian authorities say they have secured the release of the remaining 130 schoolchildren kidnapped from a Catholic boarding school in the country's central Niger state.

Nigeria's federal government described the latest release as a "moment of triumph and relief", after one of the country's worst mass kidnappings.

More than 250 children and staff were abducted from St Mary's Catholic school in Papiri on 21 November. Earlier this month, about 100 of the children were released.

The authorities confirmed "the rescue of the remaining 130 children and staff" in a statement, saying "not a single pupil is left in captivity".

Presidential spokesperson Bayo Onanuga said on Sunday the total of freed students was now 230.

Since the kidnapping, the exact number of people taken and how many have remained in captivity has been unclear.

It has not been formally made public how the government secured the latest release - or whether any ransom was paid.

The announcement by Onanuga included pictures of children smiling and waving. The students are expected to arrive in the Niger state capital, Minna, on Monday.

When the earlier release happened the governor of neighbouring Nasarawa state, Abdullahi Sule, told local media that the federal government had played a key role, adding that the behind-the-scenes efforts could not be disclosed for security reasons.

The Christian Association of Nigeria reported that 50 students managed to escape at the time of the kidnapping.

November's abduction was the latest incident in a growing number of targeted attacks on schools and places of worship in north and central Nigeria.

The attack on St Mary's in November was preceded by mass kidnappings just days earlier.

On 18 November, two people were killed and 38 abducted in an attack on the Christ Apostolic Church in Kwara state, and a day before that, two were killed, and 25 Muslim students were abducted from Government Girls' Secondary School in Kebbi state.

All those taken in the Kwara and Kebbi attacks have since been freed.

It is not clear who is behind these kidnappings - most analysts believe they are carried out by criminal gangs seeking ransom payments.

On 9 December, Nigerian President Bola Ahmed Tinubu said his government would continue to work with Niger and other states "to secure our schools and make the learning environment safer and more conducive for our younger ones.