Some of the newly-released Dapchi schoolgirls board a plane in Maiduguri. Picture: Afolabi Sotunde/Reuters

Nairobi - A Nigerian minister said Wednesday that 104 of the 110 schoolgirls abducted last month by Islamist terrorist group Boko Haram in the north-eastern town of Dapchi have been returned home.

Information and Culture Minister Alhaji Lai Mohammed did not confirm the whereabouts of the remaining six girls, but said those who were freed had been identified. In addition to the schoolgirls, a further girl and a boy were released.

Mohammed denied reports that a ransom had been paid or that a prisoner swap-deal was reached to secure their release.

The government had conducted back-channel negotiations with Boko Haram that resulted in a "non-violent approach" to their release, Mohammed said in a statement. The girls were brought back by a group of militants in a convoy.

"An operational pause was observed in certain areas to ensure free passage and also that lives were not lost," the minister added.

Read: Boko Haram brought abducted schoolgirls back, say parents

Garba Shehu, an aide to President Muhammadu Buhari, told dpa that the 11 to 19-year-old girls had been returned to Yobe state by Boko Haram militants and that they were receiving medical attention.

The girls were then airlifted to the capital Abuja aboard a military transport plane.

A parent of one of the girls, who spoke on condition of anonymity, said that five of the 110 girls abducted were not among those rescued and that they may be dead. This information could not be independently verified.

Bashir Manzo, another parent whose 16-year-old daughter was among those freed, said the rescued girls were being rounded up "so that we can do a head count to know how many were returned."

The girls were taken from their school on February 19 by a group of militants who had attacked the town of Dapchi in Yobe state.

There were several parallels between this kidnapping and the abduction of a group of more than 200 children, who have come to be known as the Chibok girls, from neighbouring Borno state in 2014.