Fatima Gremah, who was among those released on Wednesday morning said they were freed by their abductors because they are Muslims.
“Boko Haram said we were lucky we were young and also Muslims,” the 13-year-old student told reporters.
“One of us who is a Christian has been left behind. They said they would keep her until she converted.
“If she converts, they will release her. She is the only one among us left behind.
The Nigerian government has so far confirmed the release of 101 of the 110 schoolgirls who were kidnapped last month February 19 by Boko Haram Islamists from their school Government Girls College in Dapchi, Yobe State, northeast Nigeria.