Friday marks the second anniversary since Islamist militant group Boko Haram kidnapped more than 200 Nigerian girls from a Government Secondary School in the town of Chibok.
The kidnapping of the 276 girls triggered the global social media campaign #BringBackOurGirls, where politicians and celebrities
In the high-profile attack that sparked a global outcry, the militant group raided the school in April 2014 while the girls were taking exams.
They loaded 276 of them onto trucks, though around 50 escaped shortly afterwards.
At this stage, 216 remain missing, but a video obtained by CNN appears to show that some appear to be alive.
This kidnapping was not unusual, as the extremist group has been blamed for the deaths of more than 5000 people across northern Nigeria since 2013, and the enslavement of thousands.
In 2015, the group kidnapped 300 elementary school students from the town of Damasak in Borno State, and they also remain missing.
Nigeria's government and military were criticised for their handling of the incident, with towns and cities across the nation witnessing protests.
Former President Goodluck Jonathan, who declined to comment on the kidnappings for almost three weeks, was criticised, and became the first sitting Nigerian President to lose an election in 2015.
Mr Jonathan's successor, President Muhammadu Buhari, ordered a new investigation into the abductions in January 2016.
