There was global outrage when Islamists seized nearly 300 girls in Nigeria’s north-eastern town of Chibok in 2014.
Most of the victims have either been freed or escaped since then, but dozens remain unaccounted for.
It appears the two hostages gave birth while in captivity, as the army said they were both found with children.
One of the abductees was seen with a child, the other with two children.
Other victims of the mass abduction have described being forced to convert to Islam and marry the group’s fighters.
The authorities said the ”intercepted Chibok girls and their children” were in a military medical facility.
They were found on Monday during military operations against extremists in north-eastern Nigeria.
In total, 276 girls seized were from their school dormitory in the middle of the night on 14 April 2014. Within hours of their kidnapping, 57 managed to escape mostly by jumping off the lorries and running off into the bushes.
It was not until May 2016 that the first girl was found. A few others have also managed to escape over the years. Between 2016 and 2018, 103 of the victims were freed following negotiations between the Nigerian government and the militants.
Campaign group Bring Back Our Girls says around 100 are still missing.
Reports indicate that the militants have recently been abandoning their remaining captives, partly due to an intense multi-national military campaign against them.
A long-running jihadist insurgency in north-eastern Nigeria has left 40,000 dead and 2.2 million displaced, according to the AFP news agency.
Many other schools and universities in the region were attacked in the years following the 2014 Chibok kidnapping.
Some of the assaults have been by jihadists – but more frequently by criminal groups known locally as “bandits”, who engage in mass abduction for ransom.
While the Nigerian government has reportedly paid Boko Haram some $3.3m (£2.4m) as ransom for Chibok girls freed in negotiations, recent school kidnappings have seen little government involvement.
Instead, parents and relatives have been left to pay the amounts demanded by the bandits for their children’s release.
