This week marks one year since more than 200 Nigerian schoolgirls were abducted by Boko Haram, the Islamist militant group whose name translates as "western education is forbidden".
A new report by the UN children's agency has revealed around 800,000 children have been forced to flee their homes as a result of the conflict in north-east Nigeria.
To highlight the plight of these children Unicef is using Snapchat to share images of drawings from children affected by the conflict in Nigeria, Chad, Niger and Cameroon.
Here are some of the children's drawings:
Peter, 15, was separated from his family in Nigeria during an attack but is able to speak with them by phone. He is now a refugee in Chad misses the landscape and the animals at home. The environment in Chad is very different from that in Nigeria. He drew a wild pig, an elephant, a lion, a snake and a rabbit.
Rita, 14, drew all her brothers and sisters. She said she misses them but she doesn't know whether they are alive or dead.
Abba, 15, drew children going to school, a school building, a snake, a fish, bananas and a pineapple. The characters with a bag in their hands are going to school, carrying school materials.
Umar drew children going to school and several classrooms. Seen in the shooting are assailants shooting at the children and schools.
Bulus drew this drawing to represent what was missing in his life during a Unicef supported psycho-social therapy session. He said: "All our houses were burnt by the people of Boko Haram. We lost everything, even our mango tree which was on the court."
Sona said: "Boko Haram people bombed the church with the pastor there. I miss a lot things, no water, no dress, no house, no books..."
Saraya said: "I miss a lot of things, but especially my little sister Lia who died in the attacks of Boko Haram in Nigeria."
Talking about his drawing, Mamoudou said: "Boko Haram people broke the legs of my father. As he ran, they shot him and his feet were broken and he was transported. We lost everything: our freezer, TV, cup, chicken, mutton, the canary."
Mouhammadou said: "I lost my brother and our baby. I also lost my bike, and our car."
Atta Hinna said: "I drew my father and my mother. I miss them a lot. I do not know if they are still alive or are dead. Since the war began I have not seen them."
Falmata drew in a Unicef supported Child Friendly Space in Dar es Salaam Refugee camp. She said "I miss playing with my brothers."
Badamassi drew a camel, a crocodile, a rabbit, an elephant, a lion, a snake and a wild pig.
Tamahan drew his classmates and his teacher, who he misses.
This was drawn by Hanutou, 13, who is fleeing the conflict in North-East Nigeria. He said: "I miss my family in Baga."
Sali, 10, said: "I miss the access to the hospital in Baga when I get sick."
Habu, 10, also misses access to the hospital when he gets sick.
Jamila drew bananas, fish, chickens and other fruits and vegetable she had access to at home.
Idrisa said: "Boko Haram bombed my computer by bombarding our home in Nigeria, they destroyed everything. It was my father's computer but we could play with. We lost our house. Now I miss the books, pencils, exercise book."
People have been asked by Unicef to share what they would miss most if they were forced from their homes on social media using the hashtag #bringbackourchildhood.
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