Events are taking place around the world to mark one year since Boko Haram militants abducted nearly 300 schoolgirls in Nigeria, sparking global outrage. The girls were kidnapped from their school in Chibok, in the northeast of the country, leading millions around the world to call for their return as the #BringBackOurGirls hashtag exploded on social media.

A number of girls later escaped the militants, who often force those abducted to convert to Islam and fight or work as sex slaves, but 219 remain missing.