Confusion over whereabouts of schoolchildren following latest attack by Islamic militants in Nigeria.
The kidnapping was one of the high-profile incidents of Boko Haram's insurgency, now in its eighth year and with little sign of ending. About 220 were abducted from their school in a night-time attack.
The girls are studying at the American University of Nigeria in Yola.
Boko Haram released 21 of the kidnapped girls last month.
One of the Nigerian schoolgirls is used to plead with the federal government to release Boko Haram militants.
Girl says all but six of the Chibok girls are alive and being held in the Sambisa Forest, which contradicts the assumption the girls had been widely scattered.
The Nigerian army have entered Sambisa Forest, thought to be Boko Haram's last stronghold.
Warplanes lead offensive into Sambisa forest, 100 km from village where Boko Haram abducted 200 girls last year.
Despite recent defeats, experts have warned that the terror group still pose a significant threat.
French reconnaissance flights are beingconducted along Nigerien and Chadian borders as part of wider Sahel strategy.
Although no one has claimed responsibility, the attack bore the hallmarks of Boko Haram.