In the past 10 years police in greater London have investigated 83 incidents of child abuse and torture linked to witchcraft and other religious rituals. Of these children, four ... were murdered during ritualised violence. One police source said more cases of this kind were coming to light - either because the problem was increasing or because the light shone on the issue had led to increased reporting of incidents. The horrific cases of child abuse are often familial and often emerge from within the African diaspora. While most of the child killings have led to perpetrators being brought to justice, others remain mysteries. Ritualised abuse involves witchcraft-style exorcisms within many different cultures, including Caribbean, Congolese and Asian communities, according to the Met. The police set up Project Violet seven years ago to target the problem and work with other agencies to raise awareness of children at risk. We know this is an under-reported crime, we know this is a hidden crime," said Det Supt Terry Sharpe, head of Scotland Yard's child abuse investigation command. "That is why Project Violet is working with communities to try to raise the awareness within the community and among professionals so people can see the danger signs."