The anti-censorship lobby group, Article Nineteen, has published a manual for African human rights activists to help them track state-sponsored violence.

The group said that increasing scrutiny of African governments' human rights records had led to an increase in covert or informal forms of repression, for which they were able to escape responsibility.

And it said that if human rights abuses could be presented as tribal clashes or violence resulting from traditional rivalries, their real nature could be concealed. Article Nineteen said the training manual had been extensively tested in South Africa, Nigeria and Kenya.

From the newsroom of the BBC World Service