Nigerian military spokesman Sani Usman said that the girl, identified as Maryam Ali Maiyanga, was discovered by troops screening escapees from Boko Haram's base in the Sambisa forest, near the Cameroon border.

"She was discovered to be carrying a 10-month-old son," named Ali, Usman said. "She has been taken to the unit's medical facility for (a) proper medical check-up."

The campaign group Bring Back Our Girls (BBOG), which has close ties to relatives of the abducted girls, confirmed the release. "We are happy with the news... We have confirmed the name of the freed girl to be among those on our data base," BBOG campaigner Aisha Yesufu told the news agency AFP. "Our hope is that the government will work towards an early release of the remaining girls so that we can bring this sad episode to a close."

The campaign group said that Maiyanga, who was number 198 on its register of the kidnapped girls, was from Askira Uba in the Borno district and was kidnapped along with her twin, who remains missing.

The rescue came just three weeks after 21 of the abducted Chibok girls were released following negotiations between the military and Boko Haram, which were brokered by the Red Cross and Switzerland.

Global condemnation

On April 14, 2014, Boko Haram kidnapped 276 girls and young women from their school dormitory in the village of Chibok in northeastern Nigeria. About 50 of the abductees successfully escaped the initial melee, but around 200 have remained missing for more than two years. The mass abduction drew global condemnation and unprecedented attention to the Boko Haram insurgency, now in its seventh year.

Aside from last month's release, the military previously managed to recover just one other of the missing schoolgirls, in May near the border of the Sambisa forest.

In August Boko Haram released a video showing dozens of young women the Islamist group claimed were the abducted Chibok pupils.

Boko Haram's seven-year insurgency to create an Islamic caliphate in northeastern Nigeria has killed some 15,000 people and displaced more than two million.

The Nigerian government has vowed to rescue the remaining girls but has come under pressure for its incapacity to do so as yet. Usman said Saturday: "It is imperative to state that troops have been working round the clock to clear remnants of Boko Haram terrorists wherever they might be hibernating and also rescue all persons held hostages by terrorists."

dm/rc (Reuters, AFP)