276 Nigerian schoolgirls kidnapped by Boko Haram militants 17 . The shocking abduction led to high profile 'bring back our girls' campaign . Many children remain in captivity , forced to fight or become sex slaves . Unicef film highlights few escapees are now in refugee camps . The charity says more than 200 girls remain in captivity .
276 Nigerian schoolgirls kidnapped by Boko Haram militants last year . The shocking abduction led to high profile 'bring back our girls' campaign . Many children remain in captivity , forced to fight or become sex slaves . Unicef film highlights few escapees are now in refugee camps . The charity says more than 200 girls remain in captivity .