The child 'witches' of the Niger Delta

Twin boys Itohowo and Kufre stand surrounded by angry villagers who believe they are bringing evil to their lives Photograph: Robin Hammond for the Observer

Imabong Etim Otoyo, the mother who abandoned her 5 year old twin boys Photograph: Robin Hammond for the Observer

Twelve-year-old William was abandoned after being labelled a witch Photograph: Robin Hammond for the Observer

Twelve-year-old William was abandoned after being labelled a witch Photograph: Robin Hammond for the Observer

Siblings Samuel, 11, Esther, 14, and Sarah, 10, were all abandoned by their parents to a life on the streets after a ‘prophetess’ - female preacher - said they were witches Photograph: Robin Hammond for the Observer

Twin brothers Utomobong and Mbotidem are 11. They were blamed for their parents' separation, beaten and thrown out of their home Photograph: Robin Hammond for the Observer

Sisters Victoria, four, and Helen, seven. They were left alone in an old shack and survived by eating leaves and grass Photograph: Robin Hammond for the Observer

Nails were driven in around the top of Etido’s head - he is about nine and rarely speaks Photograph: Robin Hammond for the Observer

Ekemini Abia is 13. Her father tied her to a tree by her ankles and left her there. She was found, half-starved, over a week later Photograph: Robin Hammond for the Observer

Angry villagers set upon Udo, 12, with a machete, accusing him of being a witch. His arm was nearly severed Photograph: Robin Hammond for the Observer

Gerry is eight. His father spat petrol over him and set him alight - he blamed Gerry’s sorcery for the loss of his job Photograph: Robin Hammond for the Observer

A large nail was driven into this girl’s head. Nwaeka is about 16, and now badly brain damaged Photograph: Robin Hammond for the Observer

Twelve-year-old Mary had acid thrown in her face after being accused of being a witch Photograph: Robin Hammond for the Observer

Mary Sudnad is 10. She was seven when her mother poured scalding water and caustic soda over her in a bid to cleanse her of witchcraft Photograph: Robin Hammond for the Observer

Eleven-year-old Mbet was abandoned by her mother when she was six after being accused of being a witch Photograph: Robin Hammond for the Observer

Chief Joe Inuaesiet, the tribal chief of Uquo and Eket. He is a rare wise voice against those who are preaching witchcraft Photograph: Robin Hammond for the Observer

Some of the 133 children who have sought refuge at the Child Rights and Rehabilitation Network, run by Sam Ikpe-Itauma and helped by the charity Stepping Stones (steppingstonesnigeria.org) Photograph: Robin Hammond for the Observer

Children at CRARN Photograph: Robin Hammond for the Observer

Pastor Joseph Ita runs the Liberty Gospel church in Eket, and believes children, including babies, become witches by being passed poisoned food Photograph: Robin Hammond for the Observer

A woman’s unborn baby is delivered during a midnight service in Akwa Ibom Photograph: Robin Hammond for the Observer