A Year After Kidnapping, Hundreds of Schoolgirls Remain Missing

— -- A year after Boko Haram militants kidnapped nearly 300 schoolgirls in the town of Chibok, international efforts have done little to stop the insurgency that now controls vast swaths of northeastern Nigeria.

Of the known 276 schoolgirls taken in April of last year, only 50 have escaped on their own, leaving 219 still missing, although unconfirmed reports have claimed 50 of the girls were seen in the Gwoza Hills three weeks ago. The failure of the Nigerian government and the international community to locate the Chibok schoolgirls reflects the many ways in which the militant group has defied a year-long campaign to defeat them.

Since April of 2014, Boko Haram has killed more than 6,000 people, controls 15 local government areas and nearly 8,000 square miles of territory, according to the Council on Foreign Relations. A UNICEF report published Monday claimed more than 1.5 million Nigerians have fled their homes in fear of Boko Haram, including 800,000 children.

Watch the video above to get a fuller picture of how Boko Haram sustained its bloody insurgency over the last year.