In the Democratic Republic of Congo the government is accused of orchestrating massacres to crush opposition to the rule of Joseph Kabila.
One soldier told NBC News' Leftfield how he and his unit took part in killings.
Young girls, men and women have been drawn into the violence, joining militias often in revenge for the loss of loved ones or due to economic problems.
In power for 17 years, Kabila is due to organise overdue elections by the end of the year, but there are fears that if this does not happen, a new wave of killings could be the result.
- See more from NBC News' Left Field documentary team.