Recently marked three years since the kidnapping of hundreds of schoolgirls from Chibok. Three years on, and many have since been released. But others remain in captivity. To commemorate the anniversary, Bring Back Our Girls campaigners gathered in the Nigerian capital, Abuja. There, they planted trees and ties symbolic ribbons around them. The campaign says people need to be reminded of plight of the girls who remain in captivity. It's believed around 200 girls remain in the militant's clutches.