Nigeria's army says it has rescued one of the Chibok schoolgirls kidnapped by Boko Haram Islamic extremists more than two years ago in a raid on a forest hideout.

Spokesman Col. Sani Kukasheka Usman said Saturday the schoolgirl was found with a baby boy born to an extremist.

It was the first army rescue of a Chibok girl.

Nigeria's government last month secured the freedom of 21 of the Chibok schoolgirls in the first such release negotiated with Boko Haram. Another girl escaped from captivity in May.

Some 276 girls were seized from a school in northeastern Chibok town in April 2014. Dozens quickly escaped.

Officials have vowed to secure the release of nearly 200 who remain captive.